18 resultados para Heat of formation

em Deakin Research Online - Australia


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Coughing and Clapping: Investigating Audience Experience explores the processes and experiences of attending live music events from the initial decision to attend through to audience responses and memories of a performance after it has happened. The book brings together international researchers who consider the experience of being an audience member from a range of theoretical and empirical perspectives. Whether enjoying a drink at a jazz gig, tweeting at a pop concert or suppressing a cough at a classical recital, audience experience is affected by motivation, performance quality, social atmosphere and group and personal identity. Drawing on the implications of these experiences and attitudes, the authors consider the question of what makes an audience, and argue convincingly for the practical and academic value of that question.

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The size of reinforced particles notably affects the electro-discharge machining (EDM) of metal matrix composites (MMCs). This paper explores the mechanism of wire EDM of MMCs with different sizes of reinforced particles as well as the corresponding unreinforced matrix material. The mechanisms of material removal, surface generation, and taper kerf formation were investigated. This study shows that the particles’ ability to protect matrix materials from the intense heat of electric arc controls the material removal rate, surface generation, and taper of kerf. The low melting point matrix material is removed very easily, but the heat resistance reinforced particles delay the removal of material and facilitate the transfer of the workpiece material to wire electrode and vice versa. Thus, the material stays longer in touch with intense heat and affects the surface generation, wire electrode wear, and width of the kerf.

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High Pressure Die Casting (HPDC) is a complex process that results in casting defects if configured improperly. However, finding out the optimal configuration is a non-trivial task as eliminating one of the casting defects (for example, porosity) can result in occurrence of other casting defects. The industry generally tries to eliminate the defects by trial and error which is an expensive and error -prone process. This paper aims to improve current modelling and understanding of defects formation in HPDC machines. We have conducted conventional die casting tests with a neural network model of HPDC machine and compared the obtained results with the current understanding of formation of porosity. While most of our findings correspond well to established knowledge in the field, some of our findings are in conflict with the previous studies of die casting.

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The exposure to fumes and gases is one of the hazards associated with welding operations. Apart from research conducted on the mechanism of fume and gas formation and the relationship between fume formation rates and common welding parameters, little is known about the exposure process during welding. This research project aimed to identify the factors that influence exposure, develop an understanding of their role in the exposure process and through this understanding formulate strategies for the effective control of exposure during welding. To address these aims a literature review and an experimental program was conducted The literature review surveyed epidemiological, toxicological and exposure data. The experimental program involved three approaches, the first, an evaluation of the factors that influence exposure by assessing a metal inert gas/mild steel welding process in a workshop setting. The second approach involved the study of exposure in a controlled environment provided by a wind tunnel and simulated welding process. The final approach was to investigate workplace conditions through an assessment of exposure and control strategies in industry. The exposure to fumes and gases during welding is highly variable and frequently in excess of the health based exposure standards. Exposure is influenced by a number of a factors including the welding process, base material, arc time, electrode, arc current, arc voltage, arc length, electrode polarity, shield gas, wire-to-metal-work distance (metal inert gas), metal transfer mode, intensity of the UV radiation (ozone), the frequency of arc ignitions (ozone), thermal buoyancy generated by the arc process, ventilation (natural and mechanical), the welding environment, the position of the welder, the welders stance, helmet type, and helmet position. Exposure occurs as a result of three processes: the formation of contaminants at or around the arc region; their transport from the arc region, as influenced by the entry and thermal expansion of shield gases, the vigorous production of contaminants, thermal air currents produced by the heat of the arc process, and ventilation; and finally the entry of contaminants into the breathing zone of the welder, as influenced by the position of the welder, the welders stance, helmet type, and the helmet position. The control of exposure during welding can be achieved by several means: through the selection of welding parameters that generate low contaminant formation rates; through the limitation of arc time; and by isolating the breathing zone of the welder from the contaminant plume through the use of ventilation, welder position or the welding helmet as a physical barrier. Effective control is achieved by careful examination of the workplace, the selection of the most appropriate control option, and motivation of the workforce.

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The thesis concerns the treatment of actuality in film and television, particularly the narrativization of actuality images, and the context of their placement within audio/visual texts. Several instances of the convergence of media form and genre are analyzed, and the conventions of classificatory systems and boundaries that pertain to film and television representations are reconsidered in light of changes in the conventions of genre. The distinction between, and convergence of fictional and non-fictional conventions of narrative are therefore central to the thesis, as are the related issues of viewer response, the nature of subjectivity in the viewer, the connectivity of text and culture, and the relations of actuality to the text. The thesis traces the narrativization of actuality through textual, formal and genre boundaries, adopting a ‘line of flight or deterritorialization’ that enables the thesis to ‘change in nature and connect with other multiplicities.’This line of flight passes through the conventional separation of genre groupings and texts, and, similarly, has been applied in the thesis as a rationale for the diminution of theoretical boundaries. A multiperpectival approach is applied to the permeability of, or transcendent relations of the analysis to the boundaries between genres, between texts and culture, and between actuality and virtual representation. In the thesis there is also a theoretical deterritorialization that consents to a pluralism of theory, which is an approach demonstrated by Deleuze and Guattari in A Thousand Plateaus. The model of multi-perspectivalism adopted in the thesis engages in establishing connections and similarities between theories, rather than emphasizing contradictory and exclusive practices. The Foucauldian notion of the rules of formation in discourse, Nichols’ theories of documentary representation of reality, Bordwell’s schematic interpretation, and several other positions are critiqued, as the line of flight embarked upon in the thesis intersects with, and passes through both textual and theoretical boundaries. The thesis consists of two parts: firstly, a location of theoretical perspective, in which the issues of theory pertaining to actuality and narrative are explicated, and the methodological approach of the thesis is defined. The second part commences with an analysis of the most familiar instances of actuality in film and television, with particular attention to documentary forms. It then engages in the analysis of films that represent actuality but which, in the process of narrativization, display a convergence of genre conventions. The films selected for analysis include Steven Speilberg's Schindler's List, (1993) Oliver Stone's JFK, (1991) and Robert Zemeckis' Forrest Gump, (1994) and Contact, (1996). Hence the thesis is concerned with the application of a pluralist theoretical approach, with, however, an emphasis on the Deleuzo-Guattarian notions of rhizome and assemblage. Within this theoretical frame, the connections between actuality and the audio/visual text are explicated, and the formation of text as ‘a rhizome with the world’, is analyzed across a range of examples.

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Dielectric relaxation measurements as a function of temperature, and of concentration in a non-coordinating solvent, the first reported for an ionic liquid, indicate a crossover in the relaxation mechanism due to varying levels of ion aggregation and the interplay of formation kinetics and relaxation dynamics of associates.

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Allosteric regulation is a fundamental mechanism of biological control. Here, we investigated the allosteric mechanism by which GTP inhibits cross-linking activity of transglutaminase 2 (TG2), a multifunctional protein, with postulated roles in receptor signaling, extracellular matrix assembly, and apoptosis. Our findings indicate that at least two components are involved in functionally coupling the allosteric site and active center of TG2, namely (i) GTP binding to mask a conformationally destabilizing switch residue, Arg-579, and to facilitate interdomain interactions that promote adoption of a compact, catalytically inactive conformation and (ii) stabilization of the inactive conformation by an uncommon H bond between a cysteine (Cys-277, an active center residue) and a tyrosine (Tyr-516, a residue located on a loop of the p-barrel 1 domain that harborst he GTP-bindings ite). Although not essential for GTP-mediated inhibition of cross-linking, this H bond enhances the rate of formation of the inactive conformer.

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Spondylocostal dysostosis (SCD) is an inherited disorder with abnormal vertebral segmentation that results in extensive hemivertebrae, truncal shortening and abnormally aligned ribs. It arises during embryonic development by a disruption of formation of somites (the precursor tissue of the vertebrae, ribs and associated tendons and muscles). Four genes causing a subset of autosomal recessive forms of this disease have been identified: DLL3 (SCDO1: MIM 277300), MESP2 (SCDO2: MIM 608681), LFNG (SCDO3: MIM609813) and HES7 (SCDO4). These genes are all essential components of the Notch signalling pathway, which has multiple roles in development and disease. Previously, only a single SCD-causative missense mutation was described in HES7. In this study, we have identified two new missense mutations in the HES7 gene in a single family, with only individuals carrying both mutant alleles being affected by SCD. In vitro functional analysis revealed that one of the mutant HES7 proteins was unable to repress gene expression by DNA binding or protein heterodimerization.

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Background
Joining the domains of practice, research and policy is an important aspect of boosting the quality performance required to tackle complex public health problems. “Joining domains” implies a departure from the linear and technocratic knowledge-translation approach. Integrating the practice, research and policy triangle means knowing its elements, appreciating the barriers, identifying possible cooperation strategies and studying strategy effectiveness under specified conditions.
This article examines the dynamic process of developing an Academic Collaborative Centre for Public Health in the Netherlands, with the objective of achieving that the three domains of policy, practice and research become working partners on an equal footing.
Method
An interpretative hermeneutic approach was used to interpret the phenomenon of collaboration at the nexus between the three domains. The project was explicitly grounded in current organizational culture and routines, applied to nexus action. In the process of examination, we used both quantitative (e.g. records) and qualitative data (e.g., interviews and observations). The data were interpreted using the Actor-Network, Institutional Re-Design and Blurring the Boundaries theories.
Results
Results show commitment at strategic level. At the tactical level, however, managers were inclined to prioritize daily routine, while the policy domain remained absent. At the operational level, practitioners learned to do PhD research in real-life practice and researchers became acquainted with problems of practice and policy, resulting in new research initiatives.
Conclusion
We conclude that working at the nexus is an ongoing process of formation and reformation. Strategies based on Institutional Re-Design theories in particular might help to more actively stimulate managers’ involvement to establish mutually supportive networks.

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Heat-reflective layered apparel or footwear constructed from various combinations of layers of materials having selected thermal and moisture transfer properties to provide improved performance characteristics. Within these various combinations, the addition of a very thin heat reflective layer, made with a metallic material such as aluminum, applied using a vacuum plasma vapor deposition method, provides a coating that will reflect infra red heat energy either back to the body or away from the body. This heat reflective coating is so thin that is does not adversely alter the original suppporting fabrics hand feel, drape,weight , strectch or breathability. Various layers manage the body heat of an individual by reflection or thermal retention while also providing moisture wicking and antimicrobial function. Other layers manage thermal isolation from the external temperatures by using materials with very low thermal conductivity in combination with waterproof layers that can also be breathable.

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The psychological contract has received substantial theoretical attention over the past two decades as a popular framework within which to examine contemporary employment relationships. Previous research mostly examines breach and violation of the psychological contract and its impact on employee organization outcomes. Few studies have employed longitudinal, prospective research designs to investigate the psychological contract and as a result, psychological contract content and formation are incompletely understood. It is argued that employment relationships may be better proactively managed with greater understanding of formation and changes in the psychological contract. We examine existing psychological contract literature to identify five key factors proposed to contribute to the formation of psychological contracts. We extend the current research by integrating these factors for the first time into a temporal model of psychological contract development.

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Praseodymium 4-hydroxycinnamate (Pr(4OHCin)3) was investigated as a novel corrosion inhibitor for steel in NaCl solutions, and found to be effective at inhibiting corrosion in both CO2-containing and naturally-aerated systems. Surface analysis results suggest that the corrosion inhibition ability of Pr(4OHCin)3 in the naturally-aerated corrosion system could be attributed to the formation of a continuous protective film. For the CO2-containing system, the corrosion inhibition efficiency of Pr(4OHCin)3 was predominantly because of formation of protective inhibiting deposits at the active electrochemical corrosion sites, in addition to a thinner surface film deposit. © 2013.

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Thermal stabilization process of polyacrylonitrile (PAN) is the slowest and the most energy-consuming step in carbon fiber production. As such, in industrial production of carbonfiber, this step is considered as amajor bottleneck in the whole process. Stabilization process parameters are usually many in number and highly constrained, leading to high uncertainty. The goal of this paper is to study and analyze the carbon fiber thermal stabilization process through presenting several effective dynamic models for the prediction of the process. The key point with using dynamic models is that using an evolutionary search technique, the heat of reaction can be optimized. The employed components of the study are Levenberg–Marquardt algorithm (LMA)-neural network (LMA-NN), Gauss–Newton (GN)-curve fitting, Taylor polynomial method, and a genetic algorithm. The results show that the procedure can effectively optimize a given PAN fiber heat of reaction based on determining the proper values of heating rampand temperature

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The properties of interfaces depend not only on the lattice misorientation, but also on the interface plane orientation. Extensive studies of grain boundaries led to the conclusion that in systems evolving by grain growth, the relative areas of different grain boundary planes are inversely correlated to their relative energies. In other words, the low energy grain boundary planes make up a larger part of the population than the higher energy grain boundary planes. The hypothesis of this work is that the interface plane orientation distribution in transformed microstructures depends more on the mechanism of formation than on the relative energy. After a discussion of methods for measuring interface plane orientations, results will be presented for lath martensite in a low carbon steel and for martensite in a Ti-6Al-4V alloy processed in two different ways to promote a displacive transformation in one case and a diffusional transformation in the other.