998 resultados para Almost Contact Manifold


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To quantify the frictional behaviour in sheet forming operations, several laboratory experiments which simulate the real forming conditions are performed. The Bending Under Tension Test is one such experiment which is often used to represent the frictional flow of sheet material around a die or a punch radius. Different mathematical representations are used to determine the coefficient of friction in the Bending Under Tension Test. In general the change in the strip thickness in passing over the die radius is neglected and the radius of curvature to thickness ratio is assumed to be constant in these equations. However, the effect of roller radius, sheet thickness and the surface pressure are also omitted in some of these equations. This work quantitatively determined the effect of roller radius and the tooling pressure on the coefficient of friction. The Bending Under Tension Test was performed using rollers with different radii and also lubricants with different properties. The tool radii were found to have a direct influence in the contact pressure. The effect of roller radius on friction was considerable and it was observed that there is a clear relationship between the contact pressure and the coefficient of friction.

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Whilst urban-dwelling individuals who seek out parks and gardens appear to intuitively understand the personal health and well-being benefits arising from `contact with nature', public health strategies are yet to maximize the untapped resource nature provides, including the benefits of nature contact as an upstream health promotion intervention for populations. This paper presents a summary of empirical, theoretical and anecdotal evidence drawn from a literature review of the human health benefits of contact with nature. Initial findings indicate that nature plays a vital role in human health and well-being, and that parks and nature reserves play a significant role by providing access to nature for individuals. Implications suggest contact with nature may provide an effective population-wide strategy in prevention of mental ill health, with potential application for sub-populations, communities and individuals at higher risk of ill health. Recommendations include further investigation of `contact with nature' in population health, and examination of the benefits of nature-based interventions. To maximize use of `contact with nature' in the health promotion of populations, collaborative strategies between researchers and primary health, social services, urban planning and environmental management sectors are required. This approach offers not only an augmentation of existing health promotion and prevention activities, but provides the basis for a socio-ecological approach to public health that incorporates environmental sustainability.

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Issue addressed: The increase in mental health disorders worldwide makes it important to recognise health promotion interventions that are effective, accessible and affordable. Although natural spaces are coming to be recognised as health-promoting settings for general populations, little is understood about the use of nature contact in treatment and care for individuals experiencing ill-health.

Methods: This paper provides a summary of key research findings and presents a case study examining the self reported health and well-being benefits of nature contact for a small clinical sample. The 'Spectrum of Interventions for Mental Health Problems and Mental Disorders' provides a conceptual framework for ordering current and future information relating to nature-based interventions.

Results: Evidence demonstrates that separately, physical activity, social connection, and contact with nature enhance human health and well-being. The case example illustrates how 'active', 'social' and 'adventurous' contact with nature may be combined within a treatment intervention to protect and enhance the health of individuals experiencing chronic mental, emotional and physical health difficulties.

Conclusions:
'Contact with nature' constitutes a health promotion strategy with potential application in prevention, early intervention, treatment and care. Recommendations include further research to investigate the benefits of nature contact within existing interventions, and the impacts of 'active' and 'social' nature contact within tailored interventions for targeted individuals and communities.

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Research on the health and wellbeing benefits of contact with animals and plants indicates the natural environment may have significant positive psychological and physiological effects on human health and wellbeing. In terms of children, studies have demonstrated that children function better cognitively and emotionally in 'green' environments and have more creative play. In Australia as well as internationally, many schools appear to be incorporating nature-based activities into their curricula, mostly via sustainability education. Although these programs appear to be successful, few have been evaluated, particularly in terms of the potential benefits to health and wellbeing. This paper reports on a pilot survey investigating the mental health benefits of contact with nature for primary school children in Melbourne, Australia. A survey of principals and teachers was conducted in urban primary schools within a 20km radius of Melbourne. As well as gathering data on the types and extent of environmental and other nature-based activities in the sample schools, items addressing the perceptions of principals and teachers of the potential effects of these activities on children's mental health and wellbeing were also included. Despite a lower than expected response rate, some interesting findings emerged. Although preliminary, results indicate that participants' perceptions of the benefits to mental health and wellbeing from participation in hands-on nature based activities at their school are positive and encompass many aspects of mental health.

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Purpose – The purpose of this research is to explore nurses' perceptions of their current skills and knowledge and training needs to identify cases of child abuse and their understanding of their roles and responsibilities in relation to child abuse. Nurses, including health visitors and midwives, have been recognised as having a key role in the protection and care of children, especially in identifying and referring possible cases of child abuse and neglect.

Design/methodology/approach
– A structured questionnaire concerning knowledge and training needs in child protection was sent to all nurses employed in a Scottish NHS Primary Care Trust (approximately 1,900), of whom one-third (667) responded. These survey results were complemented by semi-structured interviews with 99 members of the nursing workforce.

FindingsAlmost all training in child protection had been confined to health visitors, resulting in the Trust giving an implicit message that child protection is not a role in which other nurses need have any involvement. In general, those nurses who both worked with children and had involvement in child protection issues, considered themselves to be most in need of knowledge around child protection work, to have the greatest level of knowledge and to consider further training a priority.

Research limitations/implications – Nurses who had an interest or involvement in child protection work were more likely to participate in the research, which may have biased the results.

Practical implications
– Training strategies need to address the diversity of nurses' involvements in child protection work through the development of training programmes which are appropriate for different workplaces and different occupational groupings. Nurses in some settings will need to be first convinced they have the potential to play an important role in protecting children from abuse and neglect.

Originality/value – Many NHS Trusts have in recent years introduced mandatory training in child protection for all staff in contact with children. However, previously published studies have considered training issues only in respect of nurses identified as working directly with children, whereas this study explores child protection issues for all nurses employed in a primary care NHS Trust.


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While the Australian Government partly justified the introduction of a universal National Service Training Scheme for eighteen-year old males in 1951 by highlighting the threat of imminent war and the consequent need for military preparedness, advocates also believed that national service encouraged the development of a sense of civil responsibility. Its confidence in the potential of national service to promote citizenship explains why the government was so strongly committed to the scheme's universality. Nonetheless, although the government went to great lengths to enforce compliance, Aborigines and those from other "non-white" backgrounds were actively discouraged from participation and women were only reluctantly admitted to the professional army. As would be expected in this period, they were never considered for national service. An examination of the rationale for national service and the associated discourse for inclusion and exclusion not only indicates the social assumptions shaping policy-making by government and bureaucratic elites in 1950s Australia, but also reveals their wider social aspirations.

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Wear is the principal cause of tool failure in most sheet metal forming processes. It is well known that the contact pressure between the blank and the tool has a large influence on the wear of the tool, and hence the tool life. This investigation utilises the finite element method to analyse the contact pressure distribution over the die radius for a particular deep drawing process. Furthermore, the evolution of the predicted contact pressure distribution throughout the entire stroke of the punch is also examined. It was found that the majority of the process shows a steady state pressure distribution, with two characteristic peaks over the die radius, at the beginning and end of the sheet contact area. Interestingly, the initial transient contact pressure response showed extremely high localised peak pressures; more than twice that of the steady state peaks. Results are compared to wear reported in the literature, during similar experimental deep drawing processes. Finally, the significance and effect of the results on wear and wear-testing techniques are discussed.

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Nanofretting refers to cyclic movements of contact interfaces with the relative displacement amplitude at the nanometer scale, where the contact area and normal load are usually much smaller than those in fretting. Nanofretting widely exists in microelctromechanical systems (MEMS) and may become a key tribological concern besides microwear and adhesion. With a triboindenter, the nanofretting behaviors of a nickel titanium (NiTi) shape memory alloy are studied under various normal loads (1–10 mN) and tangential displacement amplitudes (2–500 nm) by using a spherical diamond tip. Similar to fretting, the nanofretting of NiTi/diamond pair can also be divided into different regimes upon various shapes of tangential force–displacement curves. The dependence of nanofretting regime on the normal load and the displacement amplitude can be summarized in a running condition nanofretting map. However, due to the surface and size effects, nanofretting operates at some different conditions, such as improved mechanical properties of materials at the nanometer scale, small apparent contact area and single-asperity contact behavior. Consequently, different from fretting, nanofretting was found to exhibit several unique behaviors: (i) the maximum tangential force in one cycle is almost unchanged during a nanofretting test, which is different from a fretting test where the maximum tangential force increases rapidly in the first dozens of cycles; (ii) the tangential stiffness in nanofretting is three orders magnitude smaller than that in fretting; (iii) the friction coefficient in nanofretting is much lower than that in fretting in slip regime; (iv) no obvious damage was observed after 50 cycles of nanofretting under a normal load of 10 mN.

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For a given sheet metal forming process, an accurate determination of the contact pressure distribution experienced is an essential step towards the estimation of tool life. This investigation utilizes finite element (FE) analysis to determine the evolution and distribution of contact pressure over the die radius, throughout the duration of a channel forming process. It was found that a typical two-peak steady-state contact pressure response exists for the majority of the process. However, this was preceded by a transient  response, which produced extremely large and localized contact pressures. Notably, it was found that the peak transient contact pressure was more than double the steady-state peak. These contact pressure results may have a significant influence on the tool wear response and therefore impact current wear testing and prediction techniques. Hence, an investigation into the validity of the predicted contact pressure was conducted.

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The supramolecular association of the previously described para-dimethylaminophenyl-substituted diorganotellurium dihalides (p-Me2NC6H4)2TeX2 (X = Cl (1), Br (2), I (3)) and (p-Me2NC6H4)RTeCl2 (R = Ph (4), p-EtOC6H4 (5)), was investigated by X-ray crystallography. Unlike almost all other structurally characterized diorganotellurium dihalides, (p-Me2NC6H4)2TeX2 (X = Cl (1), Br (2), I (3)) reveal no secondary Te∙∙∙X interactions, but X∙∙∙X interactions. The structure of (p-Me2NC6H4)PhTeCl2 (4) resembles that of Ph2TeCl2 and shows one secondary Te∙∙∙Cl contact, whereas (p-Me2NC6H4)(p-EtOC6H4)TeCl2 (5) exhibits neither secondary Te∙∙∙Cl nor Cl∙∙∙Cl interactions. The unusual structural characteristics of 1–5 are attributed to the occurrence of intermolecular Te∙∙∙π and π∙∙∙π contacts associated with quinoid π-electron delocalization across the para-dimethylaminophenyl (1–5) and para-ethoxyphenyl (5) groups.


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This review identifies significant research that has not previously been compiled. It will provide key information for decision making by park managers, forming the basis of a program of future research to overcome the limited knowledge in this area. It is part of stage two of this project, funded by the International Park Strategic Partners Group. It builds on an earlier review (completed early in 2002 with funding provided by Parks Victoria) by addressing the health and wellbeing benefits of contact with nature in a parks context, at an individual and community level.

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This article explores some aspects of the role of race and gender in shaping women postgraduate students' experience of intercultural study. It focuses on various social and cultural aspects of their sojourn. These were suggested by data from two small pilot research projects investigating the experiences of two cohorts of international women postgraduate students, the one studying in an Australian university and the other, a Canadian. The authors focus particularly on the intersections between the students' representation of themselves as women and the way they see themselves represented by their host cultures. In other words, they are interested in the students' understandings of themselves as 'other', and how this impacts on their representations of 'self'. The authors suggest that these representations reflect a process of negotiation of identity that occurs in what they call the globalising university 'contact zone'. The concept of contact zones derives from post-colonial theory. A further goal of this article, then, is to examine how such data appear when viewed from a post-colonial perspective.