Bubble size, coalescence and particle motion in flowing foams

In minerals processing, froth flotation is used to separate valuable metal minerals from ore. The efficiency of a froth to recover these valuable minerals is closely related to the bubble size distribution through the depth of the froth. Measurement of the bubble size entering the froth and at the froth surface has been achieved previously; however measurement of the bubble size within the froth is extremely difficult as the mineral laden bubble surfaces are opaque and fragile. This work developed a flowing foam column to enable new measurement techniques, in particular visual measurement of the bubble size distribution and velocity profile throughout the depth of the foam. Two phase foam systems share their structure with three phase froth flotation systems, but are transparent in a thin layer. A foam column was constructed to contain a monolayer of overflowing and coalescing foam. This enabled direct measurement of the dynamic bubble size and coalescence through image analysis. The results showed a strong link between column geometry and the foam behaviour. In addition, the measured bubble streamlines closely matched simulated results from a foam velocity model. Positron Emission Particle Tracking (PEPT) is the only existing technique to measure particle behaviour inside froths. In this work, tracer particles with different size and hydrophobicity were tracked in a foam flowing column with PEPT. The particle trajectories were verified with image analysis, thereby increasing confidence in PEPT measurements of opaque flotation systems. The results showed that as hydrophilic tracer particles passed through the foam, their trajectory was determined by the local structure and changes of the foam, such as coalescence events. A hydrophobic tracer particle was involved in drop–off and reattachment events, however in the majority of cases still overflowed with the foam. The tracer particle did not always follow the bubble streamlines of the flowing foam, taking instead the shortest path to overflow which cut across streamlines. This work has developed an experimental methodology to validate flowing foam and coalescence models and has developed the necessary techniques to interpret PEPT trajectories in froth flotation

Going Deeper with God than King David: Cultivating Intimacy Using Hymns, Classical Sacred Songs, and Contemporary Christian Music

In the time of King David, a worshipper did not have the indwelling Holy Spirit to enhance worship as worshippers have today. At present, the modern church age worship leader utilizes mostly contemporary Christian music to help lead a congregation into the presence of God. However, the Psalms, hymns, and classical sacred songs may also be used in the exploration of enhancing a worship experience. This study explores the concept of music evoking an emotional response that may allow a worshipper to surrender to an intimate relationship with God. With studies in emotion related to music, Scriptural references, professional writings on worship, and counsel from current worship pastors, the research provides a foundation in the study of intimacy with God through surrender. In music and worship, the topic of surrender and intimacy may be difficult to cultivate. Understanding how to nurture this intimacy while eliciting an emotional response through music will be a valuable resource for a worship leader in their journey of leadership

Planograph printing: its place in modern business

This item was digitized by the Internet Archive

Tall Tales: Editing Autobiographical Memories

The impact of exaggerating when sharing an autobiographical memory with another person was investigated. Literature indicates that sharing an autobiographical memory serves a social function. However no research has investigated the impact that exaggerating when sharing specific memories has on this function. Research on lying suggests that deviating from the truth would cause the listener to like the speaker less. Research on what makes a good story indicates deviating from the truth could enhance the social benefits of sharing specific autobiographical memories by increasing the quality of the story. In Study 1, participants read scenarios of a person telling a story about a previous experience. The events were shared in complete honesty, by exaggerating the events, or by adding outrageous, yet entertaining, lies. Results indicated that participants prefer entertaining stories but do not like lies. In Study 2 participants were instructed to recall the events of a video to another participant in an entertaining way, an accurate way, or without any instructions. Results indicated the use of exaggeration, personal evaluations, and less details when recalling events in an entertaining way. Telling events in an entertaining way increased closeness and predicted liking. Participants\u27 perceptions of accuracy also predicted liking. Together these findings indicated that exciting stories are preferred over boring tales if the listener is unaware of any deviations from the actual facts

People Change: Impression Management Influences Autobiographical Memories

This paper presents the results of an experiment that tested a new impression management strategy, termed memory enhancement, and the long-term implications of using memory enhancement. People often share the events that occur in their everyday lives to others in the form of stories. This research was designed to determine if people will alter the way they share previous events to create a specific impression. It is possible that using the impression management strategy of memory enhancement will create long lasting changes to the actual memory of the event. This was tested in an experiment in which participants were put into a situation in which they wanted to create a particular impression. Participants were then given a questionnaire that included questions about general self-knowledge and specific autobiographical memories. It was hypothesized that participants would respond to the questionnaire in ways that promote the desired impression with both types of information. This hypothesis was somewhat supported and provides evidence for memory enhancement. A follow up questionnaire was also administered to measure the long-term impact of memory enhancement. It was hypothesized that memory enhancement would have lasting impacts on how the specific memory is recalled. This hypothesis was also supported. Long-term implications on the self-concept are discussed and presented in a model

Skills development training and its impact on employee self-image : a case study of employee responses to training in the wholesale and retail sector in the Western Cape

Includes bibliographical references (leaves 89-94).The aim of this study was to determine what impact training, undertaken in terms of the Skills Development Act in South Africa, has on trainees. Particular attention was paid to the way in which trainees interpreted changes to their self-image, confidence and sense of self-worth. A case study approach was used to obtain information about experiences of four research participants. The study data were gathered by means of qualitative open-ended and biographical interviews

The Invisible Woman and the Silent University

Anna Eliot Ticknor (1823 – 1896) founded the first correspondence school in the United States, the Society to Encourage Studies at Home. In the fall of 1873 an educational movement was quietly initiated from her home in Boston, Massachusetts. A politically and socially sophisticated leader, she recognized the need that women felt for continuing education and understood how to offer the opportunity within the parameters afforded women of nineteenth century America. With a carefully chosen group of women and one man, Ticknor built a learning society that extended advanced educational opportunities to all women regardless of financial ability, educational background, race, geographical location, or physical ability. Through concerted effort she kept the Society and its works as quiet as she could, an invisible woman leading a “Silent University.” The silence in which Ticknor sought to cloak her Society still overshadows its work today. Ticknor’s influence spread far and wide in the educational developments of the nineteenth century and today, quite unknowingly, the field of adult education reaps the benefits of her innovations. It is rather unfortunate that educational history, particularly adult education history, has left virtually unacknowledged the rich legacy that resulted from the work of Ticknor and her beloved Society. Careful analysis of the Society’s documents and an examination of the social, historical, and political context in which it was situated reveal a vibrant, volunteer-led organization which initiated the development of correspondence education in the United States, furthered the advanced education of women, and inspired one of the greatest movements in adult education history, the Chautauqua Literary and Scientific Circle (CLSC). Left out of the literature of adult education history is the link between John Heyl Vincent, Chautauqua cofounder, and Anna Eliot Ticknor. Historical documents of the Society and writings of those closest to Vincent provide evidence to support that it was Ticknor’s vision of correspondence education which gave birth to the CLSC. Anna Eliot Ticknor and the Society to Encourage Studies at Home have never been credited neither by Vincent nor by the field of adult education for their innovations and inspiration that changed American education

Experiences of Postsecondary Students with Physical Disabilities with Online Learning

Over one tenth of students in postsecondary education have a documented disability as defined by the Americans with Disability Act. However, faculty and course designers often lack understanding of these students\u27 experiences, which leads to insufficient accommodations. The purpose of this basic qualitative study was to explore the experiences of students with physical disabilities (SWD) in online courses. The research was grounded in self-determination theory, which posits 3 basic needs for self-actualization: autonomy, competence, and relatedness. This theory in combination with universal design for learning provided a lens for exploring these experiences. Data collection included 8 interviews with postsecondary students with a physical disability. Data were coded using a combination of value codes and organized thematically. Major findings showed that SWD experience barriers in self-regulation, minimizing of their disabilities, pressure to overachieve, specific knowledge of available resources, isolation, and miscommunication. However, through proper online learning, SWD experience benefits in self-regulation, self-pacing, an increasing sense of confidence and pride, stamina, connection to peers, positive discussions, and advocacy for themselves and others. This research has implications for social change as an evidentiary tool for advocacy when exploring the benefits of taking online courses for SWD and as an awareness tool for teachers and other stakeholders in online education who wish to adapt to best practices