938 resultados para Ball-bearings.


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Highway construction works have significant bearings on all aspects of sustainability. As they typically involve huge capital funds, stakeholders tend to place all interests on the financial justifications of the project, especially when embedding sustainability principles and practices may demand significant initial investment. Increasing public awareness and government policies demand that infrastructure projects respond to environmental challenges and people start to realise the negative consequences of not to pursue sustainability. Stakeholders are now keen to identify sustainable alternatives and financial implications of including them on a whole lifecycle basis. Therefore tools that aid the evaluation of investment options, such as provision of environmentally sustainable features in roads and highways, are highly desirable. Life-cycle cost analysis (LCCA) is generally recognised as a valuable approach for investment decision making for construction works. However to date it has limited application because the current LCCA models tend to focus on economic issues alone and are not able to deal with sustainability factors. This paper reports a research on identifying sustainability related factors in highway construction projects, in quantitative and qualitative forms of a multi-criteria analysis. These factors are then incorporated into existing LCCA models to produce a new sustainability based LCCA model with cost elements specific to sustainability measures. This presents highway project stakeholders a practical tool to evaluate investment decisions and reach an optimum balance between financial viability and sustainability deliverables.

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Legal educators in Australia have increasingly become concerned with the mental health of law students. The apparent risk posed by legal education to a student’s mental health has led to the deployment of a variety of measures to address these problems. By exploring these measures as productive power relations attempting to shape law students, this paper outlines how this government of depression is achieved, and the potential costs of these power relations. It examines one central Australian text offering advice about how students and law student societies can address depression, and argues that doing so not only involves students adopting particular practices of self-government to shape their legal personae, but also relies on an extension of the power relations of legal education. In addition, this paper will link this advice — which privatises the issue of depression, responsibilises individuals and communities, privileges psychological expertise, and seeks to govern ‘at a distance’ — to broader forms of social administration that presently characterise many Western societies. Doing so allows legal educators to reflect on the effects of their attempts to govern depression, and to consider new ways of altering the power relations of legal education.

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The aim of this study was to determine whether spatiotemporal interactions between footballers and the ball in 1 vs. 1 sub-phases are influenced by their proximity to the goal area. Twelve participants (age 15.3 ± 0.5 years) performed as attackers and defenders in 1 vs. 1 dyads across three field positions: (a) attacking the goal, (b) in midfield, and (c) advancing away from the goal area. In each position, the dribbler was required to move beyond an immediate defender with the ball towards the opposition goal. Interactions of attacker-defender dyads were filmed with player and ball displacement trajectories digitized using manual tracking software. One-way repeated measures analysis of variance was used to examine differences in mean defender-to-ball distance after this value had stabilized. Maximum attacker-to-ball distance was also compared as a function of proximity-to-goal. Significant differences were observed for defender-to-ball distance between locations (a) and (c) at the moment when the defender-to-ball distance had stabilized (a: 1.69 ± 0.64 m; c: 1.15 ± 0.59 m; P < 0.05). Findings indicate that proximity-to-goal influenced the performance of players, particularly when attacking or advancing away from goal areas, providing implications for training design in football. In this study, the task constraints of football revealed subtly different player interactions than observed in previous studies of dyadic systems in basketball and rugby union.

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Research into legal education suggests that many students enter law school with ideals about using the law to achieve social change, but graduate with some cynicism regarding these ideals. It is often argued that law schools provide a negative, competitive, and conservative environment for students, pushing many away from social justice ideals towards more self-interested, vocational concerns. This article uses Michel Foucault’s work on the government of the self to suggest another way of understanding this process. It examines a range of prescriptive texts that provide students with advice about how to study law and ‘survive’ law school. In doing so, it posits that this apparent loss of social ideals does not necessarily always signify that the student has become politically conservative or has had a negative educational experience. While these legal personae may appear outwardly conservative, and indeed still reflect particular gendered or raced perspectives, by examining the messages that these texts offer students, this article suggests that an apparent loss of social ideals can be the result of a productive shaping of the self. The legal persona they fashion can incorporate social justice ideals and necessitate specific ways of acting on those ideals. This analysis adds to the growing body of research that uses Foucault’s work to rethink common narratives of power and the shaping of the self in legal education, and provides legal educators with new ways of reflecting on the effects of legal education.

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It appears that few of the students holding ‘socially idealistic’ goals upon entering law school actually maintain these upon graduation. The critical legal narrative, which explains and seeks to act upon this shift in the graduate’s ‘legal identity’, posits that these ideals are repressed through power relations that create passive receptacles into which professional ideologies can be deposited, in the interests of those advantaged by the social and legal status quo. Using the work of Michel Foucault, this paper unpacks the assumptions underpinning this narrative, particularly its arguments about ideology, power, and the subject. In doing so, it will argue this narrative provides an untenable basis for political action within legal education. By interrogating this narrative, this paper provides a new way of understanding the construction of the legal identity through legal education, and a new basis for political action within law school.

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This article explores power within legal education scholarship. It suggests that power relations are not effectively reflected on within this scholarship, and it provokes legal educators to consider power more explicitly and effectively. It then outlines in-depth a conceptual and methodological approach based on Michel Foucault’s concept of ‘governmentality’ to assist in such an analysis. By detailing the conceptual moves required in order to research power in legal education more effectively, this article seeks to stimulate new reflection and thought about the practice and scholarship of legal education, and allow for political interventions to become more ethically sensitive and potentially more effective.

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Australia is currently in the midst of a major resources boom. However the benefits from the boom are unevenly distributed, with state governments collecting billions in royalties, and mining companies billions in profits. The costs are borne mostly at a local level by regional communities on the frontier of the mining boom, surrounded by thousands of men housed in work camps. The escalating reliance on non–resident workers housed in camps carries significant risks for individual workers, host communities and the provision of human services and infrastructure. These include rising rates of fatigue–related death and injuries, rising levels of alcohol–fuelled violence, illegally erected and unregulated work camps, soaring housing costs and other costs of living, and stretched basic infrastructure undermining the sustainability of these towns. But these costs have generally escaped industry, government and academic scrutiny. This chapter directs a critical gaze at the hopelessly compromised industry–funded research vital to legitimating the resource sector’s self–serving knowledge claims that it is committed to social sustainability and corporate responsibility. The chapter divides into two parts. The first argues that post–industrial mining regimes mask and privatise these harms and risks, shifting them on to workers, families and communities. The second part links the privatisation of these risks with the political economy of privatised knowledge embedded in the approvals process for major resource sector projects.

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Australia has always made claims to being a just and fair society. It is a land of opportunity, where anyone can make it, and where mateship rather than class underpins social relations. Why is it, then, that our criminal justice system is host to the most disadvantaged and disenfranchised in our community? Why do certain groups of people continue to experience the worst forms of injustice in our society? And why do these injustices continue, despite numerous attempts by researchers and activists to address them? By exploring the ways in which we think about justice in the wider Australian society, this book considers these questions. As disciplines that have the most to say about justice and injustice, it analyses the contributions of political philosophy and sociology, and examines how their ideas have come to dominate discussion on issues ranging from asylum seeking to homophobic violence. By examining the shared assumptions about justice and injustice that underpin these discussions, this book also charts a course between and beyond these debates, and seeks to engage, challenge, and offer new possibilities for justice in Australian society. Relevant contemporary social issues like sex trafficking, homelessness, mental illness and Indigenous policing are examined throughout, placed in their historical, social and cultural context, and linked to local, national and global debates. Such analyses examine the broader implications of these criminological, social and legal issues for those excluded from justice in Australian society.

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Spatial navigation requires the processing of complex, disparate and often ambiguous sensory data. The neurocomputations underpinning this vital ability remain poorly understood. Controversy remains as to whether multimodal sensory information must be combined into a unified representation, consistent with Tolman's "cognitive map", or whether differential activation of independent navigation modules suffice to explain observed navigation behaviour. Here we demonstrate that key neural correlates of spatial navigation in darkness cannot be explained if the path integration system acted independently of boundary (landmark) information. In vivo recordings demonstrate that the rodent head direction (HD) system becomes unstable within three minutes without vision. In contrast, rodents maintain stable place fields and grid fields for over half an hour without vision. Using a simple HD error model, we show analytically that idiothetic path integration (iPI) alone cannot be used to maintain any stable place representation beyond two to three minutes. We then use a measure of place stability based on information theoretic principles to prove that featureless boundaries alone cannot be used to improve localization above chance level. Having shown that neither iPI nor boundaries alone are sufficient, we then address the question of whether their combination is sufficient and - we conjecture - necessary to maintain place stability for prolonged periods without vision. We addressed this question in simulations and robot experiments using a navigation model comprising of a particle filter and boundary map. The model replicates published experimental results on place field and grid field stability without vision, and makes testable predictions including place field splitting and grid field rescaling if the true arena geometry differs from the acquired boundary map. We discuss our findings in light of current theories of animal navigation and neuronal computation, and elaborate on their implications and significance for the design, analysis and interpretation of experiments.

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GLBTI (gay, lesbian, bisexual, transgender, intersex) police liaison programs have been an important part of policing these communities for a number of decades now. In fact, this model appears to dominate approaches as the preferred way to manage relationships between GLBTI communities and police. Interestingly, while this model dominates, research on the effectiveness of this model, and the services that align with it, is limited. To date, only few studies have asked critical questions about the effectiveness of GLBTI police liaison services. For instance, we know that over 70% of GLBTI communities are aware of police liaison services, but only 4% of those victimised access them (Berman & Robinson, 2010). This paper critically examines existing literature about GLBTI police liaison services to demonstrate key themes and omissions. It argues that police liaison services as a preferred model has been taken for granted as the correct way of engaging with GLBTI communities in ways that may exclude other forms of engagement, and suggests that further research into these liaison programs is necessary if the relationships between GLBTI communities and the police are to be strengthened.

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This study examined physiological and performance effects of pre-cooling on medium-fast bowling in the heat. Ten, medium-fast bowlers completed two randomised trials involving either cooling (mixed-methods) or control (no cooling) interventions before a 6-over bowling spell in 31.9±2.1°C and 63.5±9.3% relative humidity. Measures included bowling performance (ball speed, accuracy and run-up speeds), physical characteristics (global positioning system monitoring and counter-movement jump height), physiological (heart rate, core temperature, skin temperature and sweat loss), biochemical (serum concentrations of damage, stress and inflammation) and perceptual variables (perceived exertion and thermal sensation). Mean ball speed (114.5±7.1 vs. 114.1±7.2 km · h−1; P = 0.63; d = 0.09), accuracy (43.1±10.6 vs. 44.2±12.5 AU; P = 0.76; d = 0.14) and total run-up speed (19.1±4.1 vs. 19.3±3.8 km · h−1; P = 0.66; d = 0.06) did not differ between pre-cooling and control respectively; however 20-m sprint speed between overs was 5.9±7.3% greater at Over 4 after pre-cooling (P = 0.03; d = 0.75). Pre-cooling reduced skin temperature after the intervention period (P = 0.006; d = 2.28), core temperature and pre-over heart rates throughout (P = 0.01−0.04; d = 0.96−1.74) and sweat loss by 0.4±0.3 kg (P = 0.01; d = 0.34). Mean rating of perceived exertion and thermal sensation were lower during pre-cooling trials (P = 0.004−0.03; d = 0.77−3.13). Despite no observed improvement in bowling performance, pre-cooling maintained between-over sprint speeds and blunted physiological and perceptual demands to ease the thermoregulatory demands of medium-fast bowling in hot conditions.

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This investigation examined physiological and performance effects of cooling on recovery of medium-fast bowlers in the heat. Eight, medium-fast bowlers completed two randomised trials, involving two sessions completed on consecutive days (Session 1: 10-overs and Session 2: 4-overs) in 31 ± 3°C and 55 ± 17% relative humidity. Recovery interventions were administered for 20 min (mixed-method cooling vs. control) after Session 1. Measures included bowling performance (ball speed, accuracy, run-up speeds), physical demands (global positioning system, counter-movement jump), physiological (heart rate, core temperature, skin temperature, sweat loss), biochemical (creatine kinase, C-reactive protein) and perceptual variables (perceived exertion, thermal sensation, muscle soreness). Mean ball speed was higher after cooling in Session 2 (118.9 ± 8.1 vs. 115.5 ± 8.6 km · h−1; P = 0.001; d = 0.67), reducing declines in ball speed between sessions (0.24 vs. −3.18 km · h−1; P = 0.03; d = 1.80). Large effects indicated higher accuracy in Session 2 after cooling (46.0 ± 11.2 vs. 39.4 ± 8.6 arbitrary units [AU]; P = 0.13; d = 0.93) without affecting total run-up speed (19.0 ± 3.1 vs. 19.0 ± 2.5 km · h−1; P = 0.97; d = 0.01). Cooling reduced core temperature, skin temperature and thermal sensation throughout the intervention (P = 0.001–0.05; d = 1.31–5.78) and attenuated creatine kinase (P = 0.04; d = 0.56) and muscle soreness at 24-h (P = 0.03; d = 2.05). Accordingly, mixed-method cooling can reduce thermal strain after a 10-over spell and improve markers of muscular damage and discomfort alongside maintained medium-fast bowling performance on consecutive days in hot conditions.

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This study investigated compound spatial and temporal measures of interpersonal interactions purported to constrain the emergence of affordances for passing direction in the team sport of futsal. For this purpose, attacker–defender interactions in 37 sequences of play from a futsal competition in which 24 male professional players participated (M=30.04 years, SD=4.10) were filmed and analysed using TACTO software. Relative angle data were used as measures to study coordination tendencies that emerged between players during performance. Results showed that the direction for a pass emerged from relative angles between: (1) the vector from a ball carrier to ball receiver and the vector from the ball carrier to the nearest defender (70°) (p<0.01) and (2) the vector from a ball carrier to ball receiver and the vector from the ball carrier to a ball receiver's nearest defender (31°) (p < 0.01). Furthermore, passing direction was also constrained by temporal information from the emergence of both angles, since the pass was performed to attacker–defender dyads with the highest velocities of these angles (p < 0.05). Results suggested that decisions on selecting the direction of a pass in the team sport of futsal emerged at critical values of these key compound motion measures.