title: Quantitative characterization of the multiscale mechanical properties of low-permeability sandstone roofs of coal seams based on nanoindentation and triaxial tests and its implications for CO2 geological sequestration

authors: Cao, F

abstract: Microstructural heterogeneity of low-permeability sandstone roofs of deep unmineable coal seams due to diagenesis significantly affects rock mechanical behavior, greatly impacting the sealing potential of in situ CO2 sequestration and the structural stability of the geological formation. However, little is known about how the microstructure of different mineral groups influences the multiscale mechanical behavior of deep sandstone. This study proposes a new method for quantitatively characterizing the multiscale mechanical properties of low-permeability sandstone and shows the mechanisms responsible for mechanical failure at the micro-, meso-, and macroscale. Triaxial compression tests and targeted nanoindentation tests were conducted to assess the micro- and macroscale mechanical properties of different types of sandstone. The micro- and macroscale experiments were coupled with numerical simulations of compression using a unified cohesive model based on Voronoi polygons to clarify the multiscale mechanical behavior. The results indicate that quartz, the primary mineral component of the sandstones examined, exhibits the strongest micromechanical properties, followed by feldspar, calcite, and clay minerals. Compared to polycrystalline quartz, monocrystalline quartz has a more stable microstructure and is mechanically stronger. The macro-mechanical properties of tight sandstone samples are weakened by increased microstructural inhomogeneity and larger grain size. This leads to a higher likelihood of splitting damage, characterized by a high degree of discrete and weak stress sensitivity. The major conclusion is that the positive rhythm lithofacies of medium-grained sandstone to siltstone are the most favorable for efficient CO2 sequestration in deep unmineable coal seams.

text: Quantitative characterization of the multiscale mechanical properties of low-permeability sandstone roofs of coal seams based on nanoindentation and triaxial tests and its implications for CO2 geological sequestration Microstructural heterogeneity of low-permeability sandstone roofs of deep unmineable coal seams due to diagenesis significantly affects rock mechanical behavior, greatly impacting the sealing potential of in situ CO2 sequestration and the structural stability of the geological formation. However, little is known about how the microstructure of different mineral groups influences the multiscale mechanical behavior of deep sandstone. This study proposes a new method for quantitatively characterizing the multiscale mechanical properties of low-permeability sandstone and shows the mechanisms responsible for mechanical failure at the micro-, meso-, and macroscale. Triaxial compression tests and targeted nanoindentation tests were conducted to assess the micro- and macroscale mechanical properties of different types of sandstone. The micro- and macroscale experiments were coupled with numerical simulations of compression using a unified cohesive model based on Voronoi polygons to clarify the multiscale mechanical behavior. The results indicate that quartz, the primary mineral component of the sandstones examined, exhibits the strongest micromechanical properties, followed by feldspar, calcite, and clay minerals. Compared to polycrystalline quartz, monocrystalline quartz has a more stable microstructure and is mechanically stronger. The macro-mechanical properties of tight sandstone samples are weakened by increased microstructural inhomogeneity and larger grain size. This leads to a higher likelihood of splitting damage, characterized by a high degree of discrete and weak stress sensitivity. The major conclusion is that the positive rhythm lithofacies of medium-grained sandstone to siltstone are the most favorable for efficient CO2 sequestration in deep unmineable coal seams.

year: 2025

title: Understanding adherence to physiotherapy: findings from an experimental simulation and an observational clinical study

authors: Tijou, Imogen

subjects: adherence

abstract: This article reports two studies assessing the influence of self-efficacy, outcome expectancies and aversive feedback on different aspects of adherence. Study 1 employed a computer simulation of physiotherapy to test experimentally the effects of aversive feedback (i.e., loud noise) experienced during simulated therapy on adherence behaviour in a student population. Study 2 examined whether similar effects of aversive feedback (i.e., pain) experienced during physiotherapy in a clinical setting would be observed in a longitudinal questionnaire study of predictors of adherence. In both studies, self-efficacy and outcome expectancies were assessed at baseline and after experience of the task (performing simulated or actual physiotherapy). Study 1 found that self-efficacy and outcome expectancies predicted persistence with simulated physiotherapy (i.e., completing the experimental session), whereas aversive feedback influenced adherence during sessions (i.e., correct response rate). Study 2 found that self-efficacy and outcome expectancies predicted persistence with actual physiotherapy (i.e., completing the prescribed number of sessions). Aversive feedback and outcome expectancies influenced adherence during sessions. We conclude that different factors predict different aspects of adherence behaviour. It is therefore important to measure both persistence over time and adherence during sessions, and to investigate the predictors of each dimension of adherence.

text: Understanding adherence to physiotherapy: findings from an experimental simulation and an observational clinical study This article reports two studies assessing the influence of self-efficacy, outcome expectancies and aversive feedback on different aspects of adherence. Study 1 employed a computer simulation of physiotherapy to test experimentally the effects of aversive feedback (i.e., loud noise) experienced during simulated therapy on adherence behaviour in a student population. Study 2 examined whether similar effects of aversive feedback (i.e., pain) experienced during physiotherapy in a clinical setting would be observed in a longitudinal questionnaire study of predictors of adherence. In both studies, self-efficacy and outcome expectancies were assessed at baseline and after experience of the task (performing simulated or actual physiotherapy). Study 1 found that self-efficacy and outcome expectancies predicted persistence with simulated physiotherapy (i.e., completing the experimental session), whereas aversive feedback influenced adherence during sessions (i.e., correct response rate). Study 2 found that self-efficacy and outcome expectancies predicted persistence with actual physiotherapy (i.e., completing the prescribed number of sessions). Aversive feedback and outcome expectancies influenced adherence during sessions. We conclude that different factors predict different aspects of adherence behaviour. It is therefore important to measure both persistence over time and adherence during sessions, and to investigate the predictors of each dimension of adherence.

year: 2008

title: Māori Women and Gambling: Every Day is a War Day!

authors: Morrison, Laurie Elena

subjects: Maori

abstract: This study was concerned with the health implications of new forms of gambling such as casinos, pokie machines and internet gambling for Māori women and their families in Auckland and the Bay of Plenty region of Aotearoa (New Zealand). It set out to discover what culturally appropriate services were available and the extent to which Māori women gamblers were utilising them. The literature documenting Māori perceptions of gambling shows that Māori women gamblers and their partner/whānau members and gambling service providers have been little studied previously.
These goals translated into the following specific aims: 1) to study how Māori women problem gamblers, their partner or whānau members and key informants perceived gambling, what it meant to them and why they did it; 2) to investigate the consequences of gambling for Māori women, whānau and service providers in dealing with the effects of gambling; 3) to report on how these three groups dealt with the effects of gambling; and 4) to discover what helped to bring about positive changes for the three groups.
 All of the aims were achieved. 
A Māori approach (Kaupapa Māori), combined with a naturalistic approach to data collection, was adopted. Qualitative methods are most appropriate to use when working with some Māori, as there is a growing realisation that research with Māori needs to be interactive. A Māori research procedure modelled on the ritual ceremony of encounter (Pōwhiri) provided an appropriate structure for the development and presentation of the research process. The major focus was on the qualitative data obtained from semi-structured interviews in two locations - Rotorua and Auckland. The interviews were conducted with twenty Māori women gamblers, sixteen whānau members including partners and ten interviews with staff involved in services that provided help for problem gamblers. The three interview schedules were based on a number of broad themes and open-ended questions to obtain meaningful descriptive data. The interviews were audio recorded and used to produce transcripts that were then sent back to the participants for feedback. Qualitative data analysis was conducted on the returned documents. 
The findings from this study revealed major impacts of the women's socio-economic, familial and societal circumstances on gambling behaviour and its effects, which are areas of concern for mental health professionals and researchers. The mythical Māori canoes on which Māori voyaged from their place of origin (Hawaiiki) to Aotearoa, the Waka, provided an appropriate metaphor to present the interrelationship between the pull and push factors toward gambling, and its implications for society. This is illustrated as a spinning waka, Te Waka Hūrihuri. On the other hand, Te Waka Māia (courageous) demonstrates the relationships between the variables that help Māori women gamblers to cope and helpful strategies found to assist them to modify or stop their gambling behaviour. It is recommended that the government limit the proliferation of gaming venues and continue to encourage development of emerging Māori services. Moreover, a coordinated approach is essential, as Māori women gamblers, partners and whānau members need to heal together for positive outcomes for Māori health development in Aotearoa. 
The main implication of this study is that a wide range of further research into Māori and gambling is required. Recommendations on ways in which the current delivery of services in Rotorua and Auckland could be improved are:
 	That the Ministry of Health purchase services that establish support groups for Māori people with problem gambling and their whānau, and
 	That non-Māori provider services and organisations support the development of emerging Māori services.
Heeding the outcome of this research should help improve New Zealand's existing health policy and capacity for Māori women's health development. It should also enrich our understanding of the adaptation patterns of Māori whānau member/s, and thus should have implications, not only for Māori health policies, but also relevance for the wider field of international cross-comparative research on indigenous gambling and mental health issues.  Limitations of this study included a small, localised sample that means the findings can only tentatively be generalised to the wider population of Māori women gamblers. Nonetheless, information gained from the study contributes to understanding of the adaptation patterns of Māori women gamblers, their whānau member/s, and those who are trying to help them.  It is hoped that the study will make it at least a little less true that  every day is a war day  for Māori women and their whānau trying to deal with the problem of gambling.

text: Māori Women and Gambling: Every Day is a War Day! This study was concerned with the health implications of new forms of gambling such as casinos, pokie machines and internet gambling for Māori women and their families in Auckland and the Bay of Plenty region of Aotearoa (New Zealand). It set out to discover what culturally appropriate services were available and the extent to which Māori women gamblers were utilising them. The literature documenting Māori perceptions of gambling shows that Māori women gamblers and their partner/whānau members and gambling service providers have been little studied previously.
These goals translated into the following specific aims: 1) to study how Māori women problem gamblers, their partner or whānau members and key informants perceived gambling, what it meant to them and why they did it; 2) to investigate the consequences of gambling for Māori women, whānau and service providers in dealing with the effects of gambling; 3) to report on how these three groups dealt with the effects of gambling; and 4) to discover what helped to bring about positive changes for the three groups.
 All of the aims were achieved. 
A Māori approach (Kaupapa Māori), combined with a naturalistic approach to data collection, was adopted. Qualitative methods are most appropriate to use when working with some Māori, as there is a growing realisation that research with Māori needs to be interactive. A Māori research procedure modelled on the ritual ceremony of encounter (Pōwhiri) provided an appropriate structure for the development and presentation of the research process. The major focus was on the qualitative data obtained from semi-structured interviews in two locations - Rotorua and Auckland. The interviews were conducted with twenty Māori women gamblers, sixteen whānau members including partners and ten interviews with staff involved in services that provided help for problem gamblers. The three interview schedules were based on a number of broad themes and open-ended questions to obtain meaningful descriptive data. The interviews were audio recorded and used to produce transcripts that were then sent back to the participants for feedback. Qualitative data analysis was conducted on the returned documents. 
The findings from this study revealed major impacts of the women's socio-economic, familial and societal circumstances on gambling behaviour and its effects, which are areas of concern for mental health professionals and researchers. The mythical Māori canoes on which Māori voyaged from their place of origin (Hawaiiki) to Aotearoa, the Waka, provided an appropriate metaphor to present the interrelationship between the pull and push factors toward gambling, and its implications for society. This is illustrated as a spinning waka, Te Waka Hūrihuri. On the other hand, Te Waka Māia (courageous) demonstrates the relationships between the variables that help Māori women gamblers to cope and helpful strategies found to assist them to modify or stop their gambling behaviour. It is recommended that the government limit the proliferation of gaming venues and continue to encourage development of emerging Māori services. Moreover, a coordinated approach is essential, as Māori women gamblers, partners and whānau members need to heal together for positive outcomes for Māori health development in Aotearoa. 
The main implication of this study is that a wide range of further research into Māori and gambling is required. Recommendations on ways in which the current delivery of services in Rotorua and Auckland could be improved are:
 	That the Ministry of Health purchase services that establish support groups for Māori people with problem gambling and their whānau, and
 	That non-Māori provider services and organisations support the development of emerging Māori services.
Heeding the outcome of this research should help improve New Zealand's existing health policy and capacity for Māori women's health development. It should also enrich our understanding of the adaptation patterns of Māori whānau member/s, and thus should have implications, not only for Māori health policies, but also relevance for the wider field of international cross-comparative research on indigenous gambling and mental health issues.  Limitations of this study included a small, localised sample that means the findings can only tentatively be generalised to the wider population of Māori women gamblers. Nonetheless, information gained from the study contributes to understanding of the adaptation patterns of Māori women gamblers, their whānau member/s, and those who are trying to help them.  It is hoped that the study will make it at least a little less true that  every day is a war day  for Māori women and their whānau trying to deal with the problem of gambling.

year: 2008