Rhonda Shaw - Academia.edu (original) (raw)

Papers by Rhonda Shaw

Research paper thumbnail of Age-related change in visual, spatial and verbal memory

Australasian Journal on Ageing, Mar 1, 2006

Research paper thumbnail of Interference in visual memory for abstract stimuli and everyday objects

Research paper thumbnail of Differential influences of the facets of religious and spiritual beliefs on Salvation Army officers’ quality of life

Journal for the Study of Spirituality, Jan 2, 2018

Salvation Army officers often work in stressful situations which are likely to impact on wellbein... more Salvation Army officers often work in stressful situations which are likely to impact on wellbeing. No research has examined the buffering effects of the officers' strong religious and spiritual beliefs on this relationship. The current study aimed to examine the relationship between quality of life (QoL) and religious and spiritual beliefs among current and retired Salvation Army officers from the Australian Eastern Territory. Two hundred and seventy officers aged between 30 and 93 years (153 males and 102 females) completed the WHOQOL-BREF 1 and the WHOQOL-SRPB. 2 The results of the analyses revealed positive relationships between religious and spiritual QoL, the eight facets of the WHOQOL-SRPB, overall QoL and each of the four WHOQOL-BREF domains. The results showed that the facets of religious and spiritual QoL made differential contributions to QoL, and the QoL domains. Hope and optimism was the only facet to predict physical and environment QoL in regression analyses. It was also a significant predictor, along with inner peace and meaning and purpose in life, of psychological QoL. Wholeness and integration, spiritual strength and faith significantly predicted the social relationship domain. However, the relationship with spiritual strength and social relationships was mediated by wholeness and integration. Spiritual connection did not significantly predict any of the QoL domains. Religious and spiritual beliefs are important for Salvation Army officers maintaining a high level of QoL in the face of stressful work environments. However, the different facets of religion and spirituality play different roles in this relationship and need to be examined individually. This is particularly important given that religious and spiritual beliefs may help officers cope with stressful work situations.

Research paper thumbnail of Ageing in corrective services: from the perspective of prison chaplains

Psychiatry, Psychology and Law, Jul 1, 2018

The number of older inmates in New South Wales prisons has increased over the past ten years but ... more The number of older inmates in New South Wales prisons has increased over the past ten years but it is unclear whether corrective services can cater for the increase. The current study reports the results of a qualitative study about ageing in prison. Eight prison chaplains from four corrective facilities in NSW were interviewed using a semi-structured interview schedule. The results of a thematic analysis revealed four main themes: the system, the services, the environment and the inmate. The themes reveal a system that is not designed to cope with an ageing population. Inmates become resentful of what has happened to them rather than for the damage they have done to somebody else. The system lacks processes and programmes to enable proper rehabilitation. The issues raised by the chaplains in terms of services, the environment and the inmates decrease the possibility that an older inmate will adapt to the environment and successfully age in place.

Research paper thumbnail of Unique needs: Salvation Army officers in retirement and end-of-life care

Journal of Religion, Spirituality & Aging, Jul 13, 2017

ABSTRACT Retirement is a major life transition. On this point there is general agreement. But wha... more ABSTRACT Retirement is a major life transition. On this point there is general agreement. But what about retirement for clergy and those who serve in the church? Perhaps a few see ministry as a job; then the change would be much like a worker ceasing paid employment. However, does being ordained, having a respected leadership role in the church, and serving God bring some unique dynamics to this transition? In this article we try to identify such factors using a large sample of Australian Salvation Army officers.

Research paper thumbnail of Religion and Spirituality in End-of-Life Care

Research paper thumbnail of Systematic review of aged care interventions for older prisoners

Australasian Journal on Ageing, Dec 6, 2017

The care of older prisoners is a growing problem. This review examined aged care interventions in... more The care of older prisoners is a growing problem. This review examined aged care interventions in prisons. Methods: A systematic review was conducted following preferred reporting items for systematic reviews and metaanalyses guidelines. A total of 1186 abstracts were screened for inclusion. Quantitative and qualitative studies were included. Results: Two quantitative studies and five qualitative studies examined aged care interventions (n = 7). An intervention involving physical health activities was not effective in reducing distress compared to a control, and an intervention of psychosocial, physical and spiritual health activities for veterans was not effective when compared to a comparison group. Qualitative analysis generated themes that apply to best practices: addressing older prisoners' needs, identifying barriers for older prisoners and staff, considering the prison culture, program delivery and cultivating older prisoners and staff attitudes. Conclusion: This review found no significant interventions in prisons. However, the qualitative findings showed evidence of best practice. Policy Impact: This systematic review of aged care in prisons, both in Australia and internationally, has many policy implications. This population is growing quickly, with many unaddressed needs. Practice Impact: The care of older prisoners is a growing and significant problem. This systematic review indicates a need for better informed practices to meet a range of prisoner needs. Some examples of creative responses are given in the review.

Research paper thumbnail of Religion and Spirituality: Older Inmates

Research paper thumbnail of Towards a ‘Social Anthropology’ of End-of-Life Moral Deliberation: A Study of Australian Salvation Army Officers

Studies in Christian Ethics, May 29, 2019

A research project by the Schools of Theology and Psychology of Australia’s Charles Sturt Univers... more A research project by the Schools of Theology and Psychology of Australia’s Charles Sturt University surveyed a large sample of Salvation Army officers. This article considers survey responses to two questions relating to end-of-life care: the use of pain medications that may shorten life, and the cessation of fluid and food intake. The results of the analyses are evaluated in terms of Michael Banner’s proposal that moral theology should more assiduously converse with ‘patient ethnographic study’, which the survey instantiates to some extent. Banner’s proposal and the results of the survey are contrasted to Peter Singer’s analytical moral philosophical dictums on end-of-life care. The results are also compared to a metastudy by Andrea Rodríguez-Prat and Evert van Leeuwen of 14 ethnographic studies of those who wish to hasten death at the end of life. We conclude that respondents exemplify a form of moral reasoning that is embedded within Christian spirituality; counters the assumptions of Singer’s approach; contrasts the diminishment of ‘meaning’ at the end of life, as seen in Rodríguez-Prat and van Leeuwen; and deserves further respectful ethnographic study.

Research paper thumbnail of Age-Related Differences in Verbal, Visual and Spatial Memory: The Same or Different?

I, the undersigned, the author of this work, understand that James Cook University will make this... more I, the undersigned, the author of this work, understand that James Cook University will make this thesis available for use within the University library and, via the Australian Digital Theses network, for use elsewhere. I understand that as an unpublished work, a thesis has significant protection under the Copyright Act, and I do not wish to place any further restriction on access to this work. Signed: ______________________ Dated: _______________________ iii STATEMENT OF SOURCES DECLARATION I declare that this thesis is my own work and has not been submitted in any form for another degree or diploma at any university or other institution of tertiary education. Information derived from the published or unpublished work of others has been acknowledged in the text and a list of references is given.

Research paper thumbnail of The relationships between visuo-spatial working memory, short-term memory and personality

Research paper thumbnail of Older Adults’ Perceptions of Psychotherapy: What Is It and Who Is Responsible?

Australian Psychologist, Feb 1, 2019

This study aimed to explore older peoples' attitudes towards, and understanding of, psychotherapy... more This study aimed to explore older peoples' attitudes towards, and understanding of, psychotherapy and their willingness to seek out psychological services for themselves. Method: A total of 14 older adults, 10 women and 4 men, aged from 65 to 89 years, participated in semi-structured interviews which were guided by a set of open-ended questions. Results: Thematic analysis identified three themes: the GP as the primary but problematic access point; unfamiliar terminology/familiar concept; and changing attitudes/lingering stigma. The General Practitioner was identified as the primary contact for accessing mental health services. Most participants were reluctant to disclose emotional concerns to their doctor and GPs were seen as responsible for initiating discussions about mental health. Lack of enquiry by GPs, short consultation times and unfamiliarity with psychological terminology were considered barriers for accessing treatment. Participants mostly held positive and accepting views of psychotherapy but a lingering stigma, based on historical values of stoicism and self-reliance, was evident. Reductions in societal stigma were attributed to increased exposure to mental health information via the media, however, participants appeared to confuse psychological services with counselling as this was a term that most were familiar with. Conclusions: Health professionals need to be mindful of the terminology they use when communicating with older adults about mental health to avoid confusion. Media initiatives do lead to improved mental health literacy and a reduction of the stigma around mental illness but they also need to distinguish between available services, for example, counselling and psychological services.

Research paper thumbnail of I Think It's a Communal Thing": Men's Friendships in Later Life

The Journal of Men's Studies, 2014

Men's friendships have traditionally been described as being activity-based but little research h... more Men's friendships have traditionally been described as being activity-based but little research has examined older men's friendships. The current study aimed to explore meanings of friendship with older men who belonged to formal men's groups or not. A thematic analysis of focus group data identified three manifest themes (constructing friendship: friends, mates or acquaintances; the dynamic nature of friendship; and the importance or beneficence of friendship) and one latent theme (community of men). Friendship was constructed as a multifaceted concept contingent on context. The importance of maintaining friendships were discussed as either self-driven or the responsibility of the other. Talking to like-minded men, regardless of group membership, was valued not just for doing activities but for the emotional support it provided.

Research paper thumbnail of Changes in the organisation of working memory processes across the adult lifespan: behavioural and electrophysiological evidence

Abstracts and Proceedings of ERA 2004, 2004

In young adulthood working memory processes have been found to form highly differentiated pools o... more In young adulthood working memory processes have been found to form highly differentiated pools of cognitive resource However, it is not yet known whether this organisation changes across the adult lifespan. The proposed study will adopt an integrated behavioural and electrophysiological methodology to examine whether working memory processes dedifferentiate into a general pool of cognitive resource, or whether they remain highly differentiated, with increased age. Nine memory tasks have been designed for this purpose, three verbal, three visual and three spatial. The reliability and validity of each of these tasks will be evaluated in Experiment One. Experiment Two will examine the nature of change in verbal, visual and spatial memory across the adult life span. Structural equation modelling will be used at this stage to determine whether a multicomponent model of working memory fits the data equally well for young and older adults. Experiment three involves recording ERPs while participants are performing the different memory tasks. This integrated approach will enable some of the discrepancies between behavioural and neurophysiological data to be clarified. It will also provide valuable information about working memory and ageing.

Research paper thumbnail of Ageing in prison

Prisons and Community Corrections, 2020

Research paper thumbnail of Interference in visual memory for abstract stimuli and everyday objects

Material mixing induced by a Rayleigh-Taylor instability occurs ubiquitously in either nature or ... more Material mixing induced by a Rayleigh-Taylor instability occurs ubiquitously in either nature or engineering when a light fluid pushes against a heavy fluid, accompanying with the formation and evolution of chaotic bubbles. Its general evolution involves two mechanisms: bubble-merge and bubble-competition. The former obeys a universal evolution law and has been well-studied, while the latter depends on many factors and has not been well-recognized. In this paper, we establish a theory for the latter to clarify and quantify the longstanding open question: the dependence of bubbles evolution on the dominant factors of arbitrary density ratio, broadband initial perturbations and various material properties (e.g., viscosity, miscibility, surface tensor). Evolution of the most important characteristic quantities, i.e., the diameter of dominant bubble D and the height of bubble zone h, is derived: (i) the D expands self-similarly with steady aspect ratio β ≡ D/h ≈ (1+A)/4, depending only on dimensionless density ratio A, and (ii) the h grows quadratically with constant growth coefficient α ≡ h/(Agt 2) ≈ [2φ/ln(2η 0)] 2 , depending on both dimensionless initial perturbation amplitude η 0 and material-property-associated linear growth rate ratio φ ≡ Γ actual /Γ ideal 1. The theory successfully explains the continued puzzle about the widely varying α ∈ (0.02, 0.12) in experiments and simulations, conducted at all value of A ∈ (0, 1) and widely varying value of η 0 ∈ [10 −7 , 10 −2 ] with different materials. The good agreement between theory and experiments implies that majority of actual mixing depends on initial perturbations and material properties, to which more attention should be paid in either natural or engineering problems.

Research paper thumbnail of Religion and Spirituality in End-of-Life Care

Encyclopedia of Gerontology and Population Aging, 2021

Research paper thumbnail of The relationships between visuo-spatial working memory, short-term memory and personality

Research paper thumbnail of Perceptions of Being Old and the Ageing Process

Ageing International, 2017

Ageing anxiety is based on worry about age-related changes in one's physical appearance and the b... more Ageing anxiety is based on worry about age-related changes in one's physical appearance and the belief that old age is a phase of life in which poor physical health, pain or discomfort, sensory losses and cognitive decline are inevitable. This qualitative study aimed to explore perceptions of being an older adult and the ageing process. Six focus groups were conducted with a total of 39 participants, aged between 50 and 92 years. An inductive thematic analysis identified three manifest themes within the data: freedom/liberation, independence/ autonomy and personal responsibility/self-care, and one overarching, latent theme, continuity and change. Perceptions of ageing and old age among this group of older adults were generally positive, however, this positivity was tempered by fears about possible future declines in health and loss of independence.

Research paper thumbnail of Religion and Spirituality: A Qualitative Study of Older Adults

Ageing International, 2016

Theories of ageing have suggested that many older adults adopt different strategies to enhance th... more Theories of ageing have suggested that many older adults adopt different strategies to enhance the experience of ageing. The current study was designed to explore the perceived role of religion and spirituality as a person ages. Eight older adults, four men and four women, aged from 67 to 80 years, participated in semistructured interviews. The results from a thematic analysis revealed three manifest themes (defining religion and spirituality, the spiritual journey and being older but not feeling older) and one latent theme (faith). Religion and spirituality can play an important role in guiding the lives of older adults as well as helping them establish meaning in their lives and to cope with adverse situations. The results show that the participants see older adulthood as a period of spiritual growth and development which provides a means of compensating for losses that can result from physical decline. Keywords Religion. Spirituality. Faith. Older age. Growth. Development Ageing is often considered a time of loss and decline (Cohen and Koenig 2003) with a focus on the decrease in mental capabilities, physical function, or the loss of friends and family (MacKinlay 2001). While this focus is important for understanding the ageing process, it tends to neglect exploration of ageing as a time of growth and vitality (Baltes and Carstensen 1996; Carstensen and Charles 1998). Three theories of ageing that explore growth are socioemotional selectivity theory (Carstensen and Charles 1998), gerotranscendence theory (Tornstam 1989, 2005) and the theory of selection, optimisation and compensation (Baltes 1995). Socioemotional selectivity theory proposes that as people age they invest more time in relationships that have meaning for them rather than in those that do not. Older people may end up with fewer relationships, but the ones they have will be strong and supportive and will provide comfort as they are able to be developed and nurtured

Research paper thumbnail of Age-related change in visual, spatial and verbal memory

Australasian Journal on Ageing, Mar 1, 2006

Research paper thumbnail of Interference in visual memory for abstract stimuli and everyday objects

Research paper thumbnail of Differential influences of the facets of religious and spiritual beliefs on Salvation Army officers’ quality of life

Journal for the Study of Spirituality, Jan 2, 2018

Salvation Army officers often work in stressful situations which are likely to impact on wellbein... more Salvation Army officers often work in stressful situations which are likely to impact on wellbeing. No research has examined the buffering effects of the officers' strong religious and spiritual beliefs on this relationship. The current study aimed to examine the relationship between quality of life (QoL) and religious and spiritual beliefs among current and retired Salvation Army officers from the Australian Eastern Territory. Two hundred and seventy officers aged between 30 and 93 years (153 males and 102 females) completed the WHOQOL-BREF 1 and the WHOQOL-SRPB. 2 The results of the analyses revealed positive relationships between religious and spiritual QoL, the eight facets of the WHOQOL-SRPB, overall QoL and each of the four WHOQOL-BREF domains. The results showed that the facets of religious and spiritual QoL made differential contributions to QoL, and the QoL domains. Hope and optimism was the only facet to predict physical and environment QoL in regression analyses. It was also a significant predictor, along with inner peace and meaning and purpose in life, of psychological QoL. Wholeness and integration, spiritual strength and faith significantly predicted the social relationship domain. However, the relationship with spiritual strength and social relationships was mediated by wholeness and integration. Spiritual connection did not significantly predict any of the QoL domains. Religious and spiritual beliefs are important for Salvation Army officers maintaining a high level of QoL in the face of stressful work environments. However, the different facets of religion and spirituality play different roles in this relationship and need to be examined individually. This is particularly important given that religious and spiritual beliefs may help officers cope with stressful work situations.

Research paper thumbnail of Ageing in corrective services: from the perspective of prison chaplains

Psychiatry, Psychology and Law, Jul 1, 2018

The number of older inmates in New South Wales prisons has increased over the past ten years but ... more The number of older inmates in New South Wales prisons has increased over the past ten years but it is unclear whether corrective services can cater for the increase. The current study reports the results of a qualitative study about ageing in prison. Eight prison chaplains from four corrective facilities in NSW were interviewed using a semi-structured interview schedule. The results of a thematic analysis revealed four main themes: the system, the services, the environment and the inmate. The themes reveal a system that is not designed to cope with an ageing population. Inmates become resentful of what has happened to them rather than for the damage they have done to somebody else. The system lacks processes and programmes to enable proper rehabilitation. The issues raised by the chaplains in terms of services, the environment and the inmates decrease the possibility that an older inmate will adapt to the environment and successfully age in place.

Research paper thumbnail of Unique needs: Salvation Army officers in retirement and end-of-life care

Journal of Religion, Spirituality & Aging, Jul 13, 2017

ABSTRACT Retirement is a major life transition. On this point there is general agreement. But wha... more ABSTRACT Retirement is a major life transition. On this point there is general agreement. But what about retirement for clergy and those who serve in the church? Perhaps a few see ministry as a job; then the change would be much like a worker ceasing paid employment. However, does being ordained, having a respected leadership role in the church, and serving God bring some unique dynamics to this transition? In this article we try to identify such factors using a large sample of Australian Salvation Army officers.

Research paper thumbnail of Religion and Spirituality in End-of-Life Care

Research paper thumbnail of Systematic review of aged care interventions for older prisoners

Australasian Journal on Ageing, Dec 6, 2017

The care of older prisoners is a growing problem. This review examined aged care interventions in... more The care of older prisoners is a growing problem. This review examined aged care interventions in prisons. Methods: A systematic review was conducted following preferred reporting items for systematic reviews and metaanalyses guidelines. A total of 1186 abstracts were screened for inclusion. Quantitative and qualitative studies were included. Results: Two quantitative studies and five qualitative studies examined aged care interventions (n = 7). An intervention involving physical health activities was not effective in reducing distress compared to a control, and an intervention of psychosocial, physical and spiritual health activities for veterans was not effective when compared to a comparison group. Qualitative analysis generated themes that apply to best practices: addressing older prisoners' needs, identifying barriers for older prisoners and staff, considering the prison culture, program delivery and cultivating older prisoners and staff attitudes. Conclusion: This review found no significant interventions in prisons. However, the qualitative findings showed evidence of best practice. Policy Impact: This systematic review of aged care in prisons, both in Australia and internationally, has many policy implications. This population is growing quickly, with many unaddressed needs. Practice Impact: The care of older prisoners is a growing and significant problem. This systematic review indicates a need for better informed practices to meet a range of prisoner needs. Some examples of creative responses are given in the review.

Research paper thumbnail of Religion and Spirituality: Older Inmates

Research paper thumbnail of Towards a ‘Social Anthropology’ of End-of-Life Moral Deliberation: A Study of Australian Salvation Army Officers

Studies in Christian Ethics, May 29, 2019

A research project by the Schools of Theology and Psychology of Australia’s Charles Sturt Univers... more A research project by the Schools of Theology and Psychology of Australia’s Charles Sturt University surveyed a large sample of Salvation Army officers. This article considers survey responses to two questions relating to end-of-life care: the use of pain medications that may shorten life, and the cessation of fluid and food intake. The results of the analyses are evaluated in terms of Michael Banner’s proposal that moral theology should more assiduously converse with ‘patient ethnographic study’, which the survey instantiates to some extent. Banner’s proposal and the results of the survey are contrasted to Peter Singer’s analytical moral philosophical dictums on end-of-life care. The results are also compared to a metastudy by Andrea Rodríguez-Prat and Evert van Leeuwen of 14 ethnographic studies of those who wish to hasten death at the end of life. We conclude that respondents exemplify a form of moral reasoning that is embedded within Christian spirituality; counters the assumptions of Singer’s approach; contrasts the diminishment of ‘meaning’ at the end of life, as seen in Rodríguez-Prat and van Leeuwen; and deserves further respectful ethnographic study.

Research paper thumbnail of Age-Related Differences in Verbal, Visual and Spatial Memory: The Same or Different?

I, the undersigned, the author of this work, understand that James Cook University will make this... more I, the undersigned, the author of this work, understand that James Cook University will make this thesis available for use within the University library and, via the Australian Digital Theses network, for use elsewhere. I understand that as an unpublished work, a thesis has significant protection under the Copyright Act, and I do not wish to place any further restriction on access to this work. Signed: ______________________ Dated: _______________________ iii STATEMENT OF SOURCES DECLARATION I declare that this thesis is my own work and has not been submitted in any form for another degree or diploma at any university or other institution of tertiary education. Information derived from the published or unpublished work of others has been acknowledged in the text and a list of references is given.

Research paper thumbnail of The relationships between visuo-spatial working memory, short-term memory and personality

Research paper thumbnail of Older Adults’ Perceptions of Psychotherapy: What Is It and Who Is Responsible?

Australian Psychologist, Feb 1, 2019

This study aimed to explore older peoples' attitudes towards, and understanding of, psychotherapy... more This study aimed to explore older peoples' attitudes towards, and understanding of, psychotherapy and their willingness to seek out psychological services for themselves. Method: A total of 14 older adults, 10 women and 4 men, aged from 65 to 89 years, participated in semi-structured interviews which were guided by a set of open-ended questions. Results: Thematic analysis identified three themes: the GP as the primary but problematic access point; unfamiliar terminology/familiar concept; and changing attitudes/lingering stigma. The General Practitioner was identified as the primary contact for accessing mental health services. Most participants were reluctant to disclose emotional concerns to their doctor and GPs were seen as responsible for initiating discussions about mental health. Lack of enquiry by GPs, short consultation times and unfamiliarity with psychological terminology were considered barriers for accessing treatment. Participants mostly held positive and accepting views of psychotherapy but a lingering stigma, based on historical values of stoicism and self-reliance, was evident. Reductions in societal stigma were attributed to increased exposure to mental health information via the media, however, participants appeared to confuse psychological services with counselling as this was a term that most were familiar with. Conclusions: Health professionals need to be mindful of the terminology they use when communicating with older adults about mental health to avoid confusion. Media initiatives do lead to improved mental health literacy and a reduction of the stigma around mental illness but they also need to distinguish between available services, for example, counselling and psychological services.

Research paper thumbnail of I Think It's a Communal Thing": Men's Friendships in Later Life

The Journal of Men's Studies, 2014

Men's friendships have traditionally been described as being activity-based but little research h... more Men's friendships have traditionally been described as being activity-based but little research has examined older men's friendships. The current study aimed to explore meanings of friendship with older men who belonged to formal men's groups or not. A thematic analysis of focus group data identified three manifest themes (constructing friendship: friends, mates or acquaintances; the dynamic nature of friendship; and the importance or beneficence of friendship) and one latent theme (community of men). Friendship was constructed as a multifaceted concept contingent on context. The importance of maintaining friendships were discussed as either self-driven or the responsibility of the other. Talking to like-minded men, regardless of group membership, was valued not just for doing activities but for the emotional support it provided.

Research paper thumbnail of Changes in the organisation of working memory processes across the adult lifespan: behavioural and electrophysiological evidence

Abstracts and Proceedings of ERA 2004, 2004

In young adulthood working memory processes have been found to form highly differentiated pools o... more In young adulthood working memory processes have been found to form highly differentiated pools of cognitive resource However, it is not yet known whether this organisation changes across the adult lifespan. The proposed study will adopt an integrated behavioural and electrophysiological methodology to examine whether working memory processes dedifferentiate into a general pool of cognitive resource, or whether they remain highly differentiated, with increased age. Nine memory tasks have been designed for this purpose, three verbal, three visual and three spatial. The reliability and validity of each of these tasks will be evaluated in Experiment One. Experiment Two will examine the nature of change in verbal, visual and spatial memory across the adult life span. Structural equation modelling will be used at this stage to determine whether a multicomponent model of working memory fits the data equally well for young and older adults. Experiment three involves recording ERPs while participants are performing the different memory tasks. This integrated approach will enable some of the discrepancies between behavioural and neurophysiological data to be clarified. It will also provide valuable information about working memory and ageing.

Research paper thumbnail of Ageing in prison

Prisons and Community Corrections, 2020

Research paper thumbnail of Interference in visual memory for abstract stimuli and everyday objects

Material mixing induced by a Rayleigh-Taylor instability occurs ubiquitously in either nature or ... more Material mixing induced by a Rayleigh-Taylor instability occurs ubiquitously in either nature or engineering when a light fluid pushes against a heavy fluid, accompanying with the formation and evolution of chaotic bubbles. Its general evolution involves two mechanisms: bubble-merge and bubble-competition. The former obeys a universal evolution law and has been well-studied, while the latter depends on many factors and has not been well-recognized. In this paper, we establish a theory for the latter to clarify and quantify the longstanding open question: the dependence of bubbles evolution on the dominant factors of arbitrary density ratio, broadband initial perturbations and various material properties (e.g., viscosity, miscibility, surface tensor). Evolution of the most important characteristic quantities, i.e., the diameter of dominant bubble D and the height of bubble zone h, is derived: (i) the D expands self-similarly with steady aspect ratio β ≡ D/h ≈ (1+A)/4, depending only on dimensionless density ratio A, and (ii) the h grows quadratically with constant growth coefficient α ≡ h/(Agt 2) ≈ [2φ/ln(2η 0)] 2 , depending on both dimensionless initial perturbation amplitude η 0 and material-property-associated linear growth rate ratio φ ≡ Γ actual /Γ ideal 1. The theory successfully explains the continued puzzle about the widely varying α ∈ (0.02, 0.12) in experiments and simulations, conducted at all value of A ∈ (0, 1) and widely varying value of η 0 ∈ [10 −7 , 10 −2 ] with different materials. The good agreement between theory and experiments implies that majority of actual mixing depends on initial perturbations and material properties, to which more attention should be paid in either natural or engineering problems.

Research paper thumbnail of Religion and Spirituality in End-of-Life Care

Encyclopedia of Gerontology and Population Aging, 2021

Research paper thumbnail of The relationships between visuo-spatial working memory, short-term memory and personality

Research paper thumbnail of Perceptions of Being Old and the Ageing Process

Ageing International, 2017

Ageing anxiety is based on worry about age-related changes in one's physical appearance and the b... more Ageing anxiety is based on worry about age-related changes in one's physical appearance and the belief that old age is a phase of life in which poor physical health, pain or discomfort, sensory losses and cognitive decline are inevitable. This qualitative study aimed to explore perceptions of being an older adult and the ageing process. Six focus groups were conducted with a total of 39 participants, aged between 50 and 92 years. An inductive thematic analysis identified three manifest themes within the data: freedom/liberation, independence/ autonomy and personal responsibility/self-care, and one overarching, latent theme, continuity and change. Perceptions of ageing and old age among this group of older adults were generally positive, however, this positivity was tempered by fears about possible future declines in health and loss of independence.

Research paper thumbnail of Religion and Spirituality: A Qualitative Study of Older Adults

Ageing International, 2016

Theories of ageing have suggested that many older adults adopt different strategies to enhance th... more Theories of ageing have suggested that many older adults adopt different strategies to enhance the experience of ageing. The current study was designed to explore the perceived role of religion and spirituality as a person ages. Eight older adults, four men and four women, aged from 67 to 80 years, participated in semistructured interviews. The results from a thematic analysis revealed three manifest themes (defining religion and spirituality, the spiritual journey and being older but not feeling older) and one latent theme (faith). Religion and spirituality can play an important role in guiding the lives of older adults as well as helping them establish meaning in their lives and to cope with adverse situations. The results show that the participants see older adulthood as a period of spiritual growth and development which provides a means of compensating for losses that can result from physical decline. Keywords Religion. Spirituality. Faith. Older age. Growth. Development Ageing is often considered a time of loss and decline (Cohen and Koenig 2003) with a focus on the decrease in mental capabilities, physical function, or the loss of friends and family (MacKinlay 2001). While this focus is important for understanding the ageing process, it tends to neglect exploration of ageing as a time of growth and vitality (Baltes and Carstensen 1996; Carstensen and Charles 1998). Three theories of ageing that explore growth are socioemotional selectivity theory (Carstensen and Charles 1998), gerotranscendence theory (Tornstam 1989, 2005) and the theory of selection, optimisation and compensation (Baltes 1995). Socioemotional selectivity theory proposes that as people age they invest more time in relationships that have meaning for them rather than in those that do not. Older people may end up with fewer relationships, but the ones they have will be strong and supportive and will provide comfort as they are able to be developed and nurtured