First-principle studies of the formation and diffusion of hydrogen vacancies in magnesium hydride

Ab initio density functional theory (DFT) calculations are performed to study the formation and diffusion of hydrogen vacancies on MgH2(110) surface and in bulk. We find that the formation energies for a single H-vacancy increase slightly from the surface to deep layers. The energies for creating adjacent surface divancacies at two inplane sites and at an inplane and a bridge site are even smaller than that for the formation of a single H-vacancy, a fact that is attributed to the strong vacancy−vacancy interactions. The diffusion of an H-vacancy from an in-plane site to a bridge site on the surface has the smallest activation barrier calculated at 0.15 eV and should be fast at room temperature. The activation barriers computed for H-vacancy diffusion from the surface into sublayers are all less than 0.70 eV, which is much smaller than the activation energy for desorption of hydrogen on the MgH2(110) surface (1.78−2.80 eV/H2). This suggests that surface desorption is more likely than vacancy diffusion to be rate determining, such that finding effective catalyst on the MgH2 surface to facilitate desorption will be very important for improving overall dehydrogenation performance.

Ab initio studies of hydrogen desorption from low index magnesium hydride surface

The low index Magnesium hydride surfaces, MgH2(0 0 1) and MgH2(1 1 0), have been studied by ab intio Density Functional Theory (DFT) calculations. It was found that the MgH2(1 1 0) surface is more stable than MgH2(0 0 1) surface, which is in good agreement with the experimental observation. The H2 desorption barriers vary depending on the crystalline surfaces that are exposed and also the specific H atom sites involved – they are found to be generally high, due to the thermodynamic stability of the MgH2 system, and are larger for the MgH2(0 0 1) surface. The pathway for recombinative desorption of one in-plane and one bridging H atom from the MgH2(1 1 0) surface was found to be the lowest energy barrier amongst those computed (172 KJ/mol) and is in good agreement with the experimental estimates.

Socio-Spatial Approaches To Literacy Studies: Rethinking the Social Constitution and Politics of Space

Literacy studies have begun to examine the spatial dimension of literacy practices in a way that foregrounds space, and that considers space as constitutive to human relations and practices. This chapter provides an introduction to spatial literacy research, providing a guide to key theorists, themes, and studies that have shaped historical and new developments in spatial approaches to literacy practice and pedagogy. It begins by reconceptualising socio-spatial approaches to literacy research and defines terms. Intersections with related social theories are examined, with an emphasis on critical approaches and the politics of space. It clarifies the relationship between socio-spatial and socio-cultural paradigms, revisiting the spatial in seminal socio-cultural research. It covers new ground,including networks, flows, and deterritorialisation of literacy practice. The chapter concludes with challenges and recommendations for future language research and educational practice.

Improving statistical analysis of matched case-control studies

Matched case–control research designs can be useful because matching can increase power due to reduced variability between subjects. However, inappropriate statistical analysis of matched data could result in a change in the strength of association between the dependent and independent variables or a change in the significance of the findings. We sought to ascertain whether matched case–control studies published in the nursing literature utilized appropriate statistical analyses. Of 41 articles identified that met the inclusion criteria, 31 (76%) used an inappropriate statistical test for comparing data derived from case subjects and their matched controls. In response to this finding, we developed an algorithm to support decision-making regarding statistical tests for matched case–control studies.

Introducing Masculinity Studies to Information Systems research : the case of Gaydar

I believe that studies of men's gendered experiences of information systems are needed. In order to support this claim, I introduce the area of Masculinity Studies to Information Systems research and, using this, present an exploratory analysis of an internet dating website for gay men – Gaydar. The information system, which forms part of the Gaydar community, is shown to shape, and be shaped by the members as they accept and challenge aspects of it as related to their identities. In doing this, I show how the intertwined processes of information systems development and use contribute to the creation of diverse interpretations of masculinity within a group of men. In sum, my analysis highlights different kinds of men and different versions of masculinity that can sometimes be associated with different experiences of information systems. The implications of this work centre on the need to expand our knowledge of men's gendered experiences with information systems, to reflect upon processes of technology facilitated categorisation and to consider the influences that contribute to the roll out of particular software features along with the underlying rationales for market segmentation in the software and software-based services industries.

Alternative models of cardiac rehabilitation : a systematic review

The traditional hospital-based model of cardiac rehabilitation faces substantial challenges, such as cost and accessibility. These challenges have led to the development of alternative models of cardiac rehabilitation in recent years. The aim of this study was to identify and critique evidence for the effectiveness of these alternative models. A total of 22 databases were searched to identify quantitative studies or systematic reviews of quantitative studies regarding the effectiveness of alternative models of cardiac rehabilitation. Included studies were appraised using a Critical Appraisal Skills Programme tool and the National Health and Medical Research Council's designations for Level of Evidence. The 83 included articles described interventions in the following broad categories of alternative models of care: multifactorial individualized telehealth, internet based, telehealth focused on exercise, telehealth focused on recovery, community- or home-based, and complementary therapies. Multifactorial individualized telehealth and community- or home-based cardiac rehabilitation are effective alternative models of cardiac rehabilitation, as they have produced similar reductions in cardiovascular disease risk factors compared with hospital-based programmes. While further research is required to address the paucity of data available regarding the effectiveness of alternative models of cardiac rehabilitation in rural, remote, and culturally and linguistically diverse populations, our review indicates there is no need to rely on hospital-based strategies alone to deliver effective cardiac rehabilitation. Local healthcare systems should strive to integrate alternative models of cardiac rehabilitation, such as brief telehealth interventions tailored to individual's risk factor profiles as well as community- or home-based programmes, in order to ensure there are choices available for patients that best fit their needs, risk factor profile, and preferences.

Racial/ethnic variations in violence against women : Urban, suburban and rural differences

A large literature shows that violence against women in intimate relationships varies across racial/ethnic groups. However, it is unclear whether such variations differ across urban, suburban, and rural areas. The main objective of this article is to examine this issue using 1992 to 2009 National Crime Victimization Survey data. We also test the hypothesis that racial/ethnic minority women living in rural areas are more likely to be assaulted by their current and former intimate partners than are their urban and suburban counterparts. Contrary to expectations, results indicated virtually no differences in the rates at which urban, suburban, and rural racial/ethnic minority females were victims of intimate violence. The results indicate the great need of additional research into this important topic.

A study of postdiagnosis breast cancer concerns for women living in rural and remote Queensland. Part II : support issues

This paper presents the recent findings from a study on the postdiagnosis support needs of women with breast cancer living in rural and remote Queensland. The findings presented in this discussion focus on support needs from the perspective of the women experiencing breast cancer as well as health service providers. The tyranny of distance imposes unique hardships, such as separation from family and friends, during a time of great vulnerability for treatment, the need to travel long distances for support and follow-up services, and extra financial burdens, which can combine to cause strains on the marital relationship and family cohesion. Positive indications are, however, that the rural communities operate on strong, informal networks of support. This network of family, friends and community can, and does, play an active role in the provision of emotional and practical support.

Constructions of children's needs in informal kinship care in rural China

Kinship care is the oldest form of alternative child care in the world. Recent years have witnessed a significant increase in the number of children being placed in kinship care across Western countries. However, in contrast to rapid knowledge advances about formal kinship care, far less is known about the needs of children in informal kinship care, especially in Asian contexts. This thesis and the study upon which it is formed sought to redress this knowledge gap. Qualitative approach was adopted to explore social constructions of children in informal kinship care in rural China. Parents in China seeking work in cities have left behind around 58 million rural children, mostly with relatives and without the involvement of the state. The present study examined caregivers’ and school personnel’s understandings of these school-age children’s needs through semi-structured interviews with 23 kin caregivers and five school personnel in Shijiapu Town, Jilin Province, China. The central question that guided the whole study is: What are the needs of children in informal kinship care in rural Jilin Province, China? Interpretative Phenomenological Analysis was used to categorise and interpret the qualitative data. Based on participants’ constructions, this study developed a need model with eight themes. They are: (1) emotional needs and mental health, (2) relationships, (3) empowerment and agency, (4) safety, (5) education, (6) basic care, (7) physical health, and (8) personal development. These needs are grounded in the Chinese context, and therefore a good understanding of Chinese culture is essential to address them. The first four needs particularly capture children’s separations from their parents, and the rest are more general, and can be applied to most Chinese children. To meet the most important need for children left behind, namely education, these caregivers determined that others needs sometimes have to be compromised. Children left behind are a vulnerable group in contemporary rural China, and their diverse needs are attended to by several groups. This study found that as children’s closest kin while their parents are away, caregivers play a vital role in salving the children’s emotional loss. Caregivers’ love and familial obligations strongly motivate them to care for these children, and sensitivity to social stigma makes them strive to show their love and care to compensate for perceived differences between these children and their peers. Caregivers’ efforts to make children happy, however, were sometimes criticised by some school personnel, who see this as spoiling. The conflicting viewpoint between caregivers and school personnel indicate their different roles and perceptions in children’s lives, and the latter influence these children in a more authoritative way. Informal kinship care has several advantages of addressing children’s needs, especially their needs for emotional bonds with family. Community-based kin networks provide children with both emotional and material support. However, these advantages sometimes are restricted by caregivers’ child rearing capacity. Having developed a model of the needs of children left behind in China, this study suggests that caregivers, school personnel and government social services work in harmony to be child-centred and meet these children’s diverse needs. The unmet needs of children left behind mainly result from unbalanced development between urban and rural China, therefore, it is imperative to enhance state policies and programs that improve wellbeing for this growing part of China’s people.

Design, sustainability and Australian mass-market fashion : three case studies

The production of fashion garments has negative environmental and social impacts that can potentially be reduced through decisions made in the design process. This research explores to what extent Australian mass-market fashion designers consider environmental sustainability within product design. The study presents three case studies from different market levels, assembled through interviews with designers, along with an analysis of the Australian mass-market fashion industry. The project provides insights into the workings of the fashion design process within mid and high volume companies, and identifies opportunities and barriers for consideration of sustainability.

Towards engaged consumption : new sources of inspiration for eco-feedback design

Eco-feedback interventions are capable of producing reductions in household energy consumption. Yet less is known about exactly how this reduction is achieved, how to maximise user engagement, or how to effectively translate engagement into energy saving. This paper discusses design opportunities for eco-feedback systems through observations of domestic energy use in both Western and rural developing world contexts. Drawing on case studies from these two contexts including 21 empirical interviews, we present an alternative framework for human-resource interaction, highlighting design opportunities for a transition towards more engaged and sustainable energy consumption among users.

In situ Raman studies of the selective oxidation of methanol to formaldehyde and ethene to ethylene oxide on a polycrystalline silver catalyst

The combined techniques of in situ Raman microscopy and scanning electron microscopy (SEM) have been used to study the selective oxidation of methanol to formaldehyde and the ethene epoxidation reaction over polycrystalline silver catalysts. The nature of the oxygen species formed on silver was found to depend critically upon the exact morphology of the catalyst studied. Bands at 640, 780 and 960 cm-1 were identified only on silver catalysts containing a significant proportion of defects. These peaks were assigned to subsurface oxygen species situated in the vicinity of surface dislocations, AgIII=O sites formed on silver atoms modified by the presence of subsurface oxygen and O2 - species stabilized on subsurface oxygen-modified silver sites, respectively. The selective oxidation of methanol to formaldehyde was determined to occur at defect sites, where reaction of methanol with subsurface oxygen initially produced subsurface OH species (451 cm-1) and adsorbed methoxy species. Two distinct forms of adsorbed ethene were identified on oxidised silver sites. One of these was created on silver sites modified by the interaction of subsurface oxygen species, and the other on silver crystal planes containing a surface coverage of atomic oxygen species. The selective oxidation of ethene to ethylene oxide was achieved by the reaction between ethene adsorbed on modified silver sites and electrophilic AgIII=O species, whereas the combustion reaction was perceived to take place by the reaction of adsorbed ethene with nucleophilic surface atomic oxygen species. Defects were determined to play a critical role in the epoxidation reaction, as these sites allowed the rapid diffusion of oxygen into subsurface positions, and consequently facilitated the formation of the catalytically active AgIII=O sites.

Spectroscopic studies of the adsorption and reactions of chlorofluorocarbons (CFC-11 and CFC-12) and hydrochlorofluorocarbon (HCFC-22) on oxide surfaces

Raman and Fourier transform infrared (FT-IR) spectroscopy have been applied to a systematic investigation of the adsorption and decomposition of dichlorodifluoromethane (CCl2F2, CFC-12), fluorotrichloromethane (CCl3F, CFC-11), chlorodifluoromethane (CHClF2, HCFC-22) and molecular chlorine on oxide surfaces. Additionally, the effects of heating and ultraviolet photolysis of the CFC and HCFCs adsorbed on the oxide surfaces have been investigated. Spectral features for these species indicated a small wavenumber shift (1-6 cm-1) associated with the adsorbed phase. Some evidence, specifically the appearance of the Raman band at 507 cm-1, is presented to show that chlorine decomposition species are associated with these oxide surfaces. It was concluded that the new spectral feature (at ca. 507 cm-1) related with the decomposition of the CFC and HCFC molecules was an important indicator of the extent to which the reaction between the adsorbed CFC and HCFC and oxide surface has taken place. The extent of CFC-surface interaction has been quantified in terms of a maximum (Raman) frequency shift parameter (AM). Wavenumber shifts suggest both cation-adsorbate and non-specific adsorption interactions are occurring in the internal channels of the zeolites. Slow decomposition of the adsorbed CFCs under ultraviolet-visible photolysis (at ? > 300 nm) and/or thermal treatment was observed spectroscopically. Using FT-IR spectroscopy, the formation of gas-phase products (CO, CO2, HCl) both onyn photolysis and heating was evident. Results of these measurements are compared with the observed atmospheric reactivity of these compounds.