Grain boundaries in polycrystalline materials for energy applications: First principles modeling and electron microscopy

\ua9 2024 Author(s). Polycrystalline materials are ubiquitous in technology, and grain boundaries have long been known to affect materials properties and performance. First principles materials modeling and electron microscopy methods are powerful and highly complementary for investigating the atomic scale structure and properties of grain boundaries. In this review, we provide an introduction to key concepts and approaches for investigating grain boundaries using these methods. We also provide a number of case studies providing examples of their application to understand the impact of grain boundaries for a range of energy materials. Most of the materials presented are of interest for photovoltaic and photoelectrochemical applications and so we include a more in depth discussion of how modeling and electron microscopy can be employed to understand the impact of grain boundaries on the behavior of photoexcited electrons and holes (including carrier transport and recombination). However, we also include discussion of materials relevant to rechargeable batteries as another important class of materials for energy applications. We conclude the review with a discussion of outstanding challenges in the field and the exciting prospects for progress in the coming years

Sclerotinia sclerotiorum disease prediction: A review and potential applications in South Africa

Sclerotinia sclerotiorum is a predominant plant pathogen, with host crops of agricultural and economic importance internationally. South African host crops of importance include canola, soybean and sunflower, which contribute significantly to the South African economy. This significance emphasises the importance of effective disease management strategies, including rotation with non-host crops, planting cultivars with a degree of tolerance, and using relevant cultural and chemical practices. The sporadic nature of disease outbreaks caused by Sclerotinia spp. can complicate fungicide application timing as a result of the pathogen’s interaction with the host and environment. The use of prediction modelling for diseases caused by Sclerotinia spp. can contribute to increased fungicide application efficacy and a reduction in the number of unnecessary sprays. Predictive modelling is based upon the collection and statistical analysis of multi-locality and multi-seasonal, pathogen, disease and weather data. Incorporating the complexity of disease initiation and development into such models is dependent on selecting the correct statistical tools to interpret appropriate data, which can be used to develop a model that is accurate, precise and reliable. Internationally, forecasting models for diseases caused by Sclerotinia spp. exist and are applied commercially for multiple Sclerotinia spp. on important agricultural crops. The application of these models in a South African context has been limited but provides promise for effective disease intervention technologies. This review provides a platform to raise awareness of the potential applications of plant disease epidemiology and the use of statistics and mathematical modelling in agricultural systems. Plant disease forecasts are an important part of the future for sustainable and economically viable agronomic decisions.  Significance: • Optimisation of plant disease management through ensuring that fungicide applications coincide with disease-favourable conditions, thus targeting the disease more strategically. • The use of mathematical and statistical models to quantify the interactions among the host, pathogen and environment and predict future outbreaks of the disease. • The study of temporal and spatial interactions among the host, pathogen and environment on plant disease behaviour

Do wage and wage satisfaction compensate for the effects of a dissatisfying job on life satisfaction?

Orientation: Research regarding subjective well-being (including life satisfaction and domain-specific satisfaction) is necessary, given the effects thereof on health, work performance, social relationships and ethical behaviour of employees. Research purpose: This study aimed to investigate the relationships among life satisfaction, job satisfaction and wage satisfaction, as well as how these relationships related to gross wage category in a South African sample. Motivation for the study: While research has shown that wage level and wage satisfaction are positively associated with both job and life satisfaction, the question arises whether wage level and satisfaction would compensate for the negative effect of a dissatisfying job on life satisfaction. Research approach/design and method: A cross-sectional design was used. A non-probability convenience sample (N = 763) in the form of the WageIndicator data set was obtained. Hierarchical log-linear analyses and cross-tabulations were carried out to determine the relationships that existed among the constructs. Main findings: Although job satisfaction and wage satisfaction were strongly related at a low level of wage satisfaction, fewer people were satisfied with their jobs at a high level of wage satisfaction level. Moreover, while job and life satisfaction were strongly related at a low level of job satisfaction level, relatively fewer people were satisfied with their lives at a high level of job satisfaction level. Wage dissatisfaction was associated with dissatisfaction with life but was more strongly associated with life satisfaction at a high level of wage satisfaction. Wage category and wage satisfaction did not interact with the job satisfaction level in affecting life satisfaction. Practical/managerial implications: Managers should attend to the perceptions of wage dissatisfaction at low wage and wage satisfaction levels. Such dissatisfaction may have a negative impact on the job and life satisfaction of employees and result in detrimental effects on employees and organisations. Contribution/value-add: This study contributes to scientific knowledge regarding the relationships between wage, wage satisfaction, job dissatisfaction and life satisfaction

Stress appraisal, coping, and work engagement among police recruits: an exploratory study.

This study investigated the influence of stress appraisal and coping on work engagement levels (Absorption, Vigour, and Dedication) of police recruits. Participants were 387 men, ages 20 to 33 yr. (M = 24.1, SD = 2.4), in their last month of academy training before becoming police officers. Partially in support of predictions, work engagement was associated with Stressor control perceived, but not Stress intensity experienced over a self-selected stressor. Although the three dimensions of work engagement were explained by Stressor control and coping, Absorption was the dimension better explained by these variables. Police recruits reporting higher Absorption, Vigour, and Dedication reported using more Active coping and less Behavioural disengagement. Results showed that stress appraisal and coping are important variables influencing work engagement among police recruits. Findings suggested that future applied interventions fostering work engagement among police recruits should reinforce perceptions of control over a stressor as well as Active coping strategies

Grain boundaries in polycrystalline materials for energy applications : First principles modeling and electron microscopy

Polycrystalline materials are ubiquitous in technology, and grain boundaries have long been known to affect materials properties and performance. First principles materials modeling and electron microscopy methods are powerful and highly complementary for investigating the atomic scale structure and properties of grain boundaries. In this review, we provide an introduction to key concepts and approaches for investigating grain boundaries using these methods. We also provide a number of case studies providing examples of their application to understand the impact of grain boundaries for a range of energy materials. Most of the materials presented are of interest for photovoltaic and photoelectrochemical applications and so we include a more in depth discussion of how modeling and electron microscopy can be employed to understand the impact of grain boundaries on the behavior of photoexcited electrons and holes (including carrier transport and recombination). However, we also include discussion of materials relevant to rechargeable batteries as another important class of materials for energy applications. We conclude the review with a discussion of outstanding challenges in the field and the exciting prospects for progress in the coming years

Concepts of health and well-being in managers: An organizational study

Global changes and new managerial challenges require new concepts of health and well-being in organizational contexts. In the South African context, health and well-being of managers have gained relevance in organizations and in management sciences. International organizations, in particular, attempt to address the increasing demand for health care and the delivery of health services to their managers. Careful and appropriate health management requires research to evaluate context-specific health concepts and strategies. The purpose and aim of this article is to assess managerial concepts on health and well-being that could be used by the organization to contribute to managerial well-being by implementing health promotion according to managerial needs. At the same time, this article contributes to salutogenetic health research that is very rare with regard to the South African organizational management research

Spectral morphometric characterization of breast carcinoma cells

The spectral morphometric characteristics of standard haematoxylin and eosin breast carcinoma specimens were evaluated by light microscopy combined with a spectral imaging system. Light intensity at each wavelength in the range of 450–800 nm was recorded for 104 pixels from each field and represented as transmitted light spectra. A library of six characteristic spectra served to scan the cells and reconstruct new images depicting the nuclear area occupied by each spectrum. Fifteen cases of infiltrating ductal carcinoma and six cases of lobular carcinoma were examined; nine of the infiltrating ductal carcinoma and three of the lobular carcinoma showed an in situ component. The spectral morphometric analysis revealed a correlation between specific patterns of spectra and different groups of breast carcinoma cells. The most consistent result was that lobular carcinoma cells of in situ and infiltrating components from all patients showed a similar spectral pattern, whereas ductal carcinoma cells displayed spectral variety. Comparison of the in situ and the infiltrating ductal solid, cribriform and comedo carcinoma cells from the same patient revealed a strong similarity of the spectral elements and their relative distribution in the nucleus. The spectrum designated as number 5 in the library incorporated more than 40% of the nuclear area in 74.08% of the infiltrating lobular cells and in 13.64% of the infiltrating ductal carcinoma cells (P < 0.001). Spectrum number 2 appeared in all infiltrating ductal cells examined and in none of the lobular cells. These results indicate that spectrum number 5 is related to infiltrating lobular carcinoma, whereas spectrum number 2 is characteristic for infiltrating ductal carcinoma cells. Spectral similarity mapping of central necrotic regions of comedo type in situ carcinoma revealed nuclear fragmentation into defined segments composed of highly condensed chromatin. We conclude that the spectral morphometric features found for lobular and ductal cell populations may serve future automated histological diagnostics. © 1999 Cancer Research Campaig

The feasibility of gene therapy in the treatment of head and neck cancer

Standard approach to the treatment of head and neck cancer include surgery, chemotherapy, and radiation. More recently, dramatic increases in our knowledge of the molecular and genetic basis of cancer combined with advances in technology have resulted in novel molecular therapies for this disease. In particular, gene therapy, which involves the transfer of genetic material to cells to produce a therapeutic effect, has become a promising approach. Clinical trials concerning gene therapy strategies in head and neck cancer as well as combination of these strategies with chemotherapy and radiation therapy will be discussed