934 resultados para Moment of inertia


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The change from nursing student to Registered Nurse (RNs) is both a desirable and anticipated event for New Graduate Nurses (NGNs). Having completed their formal education, most NGNs approach the threshold of their professional career with mixed emotions. While excited about the future and eagerly awaiting the commencement of employment, many are aware that this change also signifies a time of personal upheaval, professional insecurity and further personal learning. In the nursing professions’ enthusiasm to facilitate a smooth passage for NGNs a vast literature now addresses preparation-for-practice degrees, as well as the perceived workplace deficits and support needs of NGNs. However, the importance this change from working as a student to working as a NGN is not well conceptualised, theorised or understood as this largely instrumental literature essentially reduces the problematisation of the NGN transition experience to the problematisation of the individual by identifying NGNs as ‘the’ problem. Subsequently it fails to expose or challenge the normative assumptions underpinning processes that have formerly been considered solutions, or, the impact of such processes in a workplace that frames itself as “supportive”. Conspicuously absent is an exploration of how the NGN role is performed by former students, now beginning RNs undergoing the very personal transition of “becoming registered nurses”. Using Goffman’s (1956) theorisation of performance in everyday life exploring how process and meaning in mundane interactions present themselves in the “regular” lives of people at large, and Margaret Archer’s (2000) work emphasising the significance of the inner dialogue for managing the emotions that emerge out of situations that confront us, this paper draws upon data collected during a study of NGNs’ experience of transition to practice (Malouf 2010). It focuses on an emergent understanding of the need to differentiate the performance of ‘student’ from that of ‘NGN’ role. Further, it explores how these roles have become conflated into a conceptual continuum and viewed as a slide from student to NGN performance, rather than a significant moment of change involving roles that need to be distinctly defined as a necessary precursor to enhancing and supporting the professional and personal development of beginning practitioners.

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The question of how young firms reconcile the absence of well-established learning routines arising from the “liabilities of newness” with the “learning advantages of newness” has received scant attention in entrepreneurship. While older firms follow established learning routines and sometimes face problems in overcoming inertia, young firms with lower levels of inertia are better poised to explore, search and test unique avenues for their products and services. The process of learning and capability development as well as establishing uniqueness in their product offerings is an important part not only in the early stages of firm growth, but also in firm survival. Given their inexperience, for young firms, these learning processes are iterative and include contrasting learning loops that sometimes progress and at other times digress from initially perceived unique ideas. Such processes are embedded within capabilities that the firm develops and nurtures. Based on this premise and adopting a capabilities-based view, we examine how strategic networks and environmental knowledge affects uniqueness- mediated performance in young firms. We identify firms with digressive learning strategies based on their self-assessment of learning and compare them with other firms to demonstrate a differential effect on performance.

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Dual-mode vibration of nanowires has been reported experimentally through actuation of the nanowire at its resonance frequency, which is expected to open up a variety of new modalities for the NEMS that could operate in the nonlinear regime. In the present work, we utilize large scale molecular dynamics simulations to investigate the dual-mode vibration of <110> Ag nanowires with triangular, rhombic and truncated rhombic cross-sections. By incorporating the generalized Young-Laplace equation into Euler-Bernoulli beam theory, the influence of surface effects on the dual-mode vibration is studied. Due to the different lattice spacing in principal axes of inertia of the {110} atomic layers, the NW is also modeled as a discrete system to reveal the influence from such specific atomic arrangement. It is found that the <110> Ag NW will under a dual-mode vibration if the actuation direction is deviated from the two principal axes of inertia. The predictions of the two first mode natural frequencies by the classical beam model appear underestimated comparing with the MD results, which are found to be enhanced by the discrete model. Particularly, the predictions by the beam theory with the contribution of surface effects are uniformly larger than the classical beam model, which exhibit better agreement with MD results for larger cross-sectional size. However, for ultrathin NWs, current consideration of surface effects is still experiencing certain inaccuracy. In all, for all different cross-sections, the inclusion of surface effects is found to reduce the difference between the two first mode natural frequencies. This trend is observed consistent with MD results. This study provides a first comprehensive investigation on the dual-mode vibration of <110> oriented Ag NWs, which is supposed to benefit the applications of NWs that acting as a resonating beam.

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The Gallery of Modern Art (GoMA) in Brisbane, Australia’s third largest city, recently staged ‘21st Century: Art of the First Decade’. The gallery spaces were replete with a commissioned slide by Carsten Höller, an installation of Rivane Neuenschwande’s I Wish Your Wish (2003), a table of white Legos, a room of purple balloons and other participatory or interactive artworks designed to engage multiple publics and encourage audience participation in a variety of ways. Many of the featured projects used day-to-day experiences and offered new conceptions about art practice and what they can elicit in their public – raise awareness about local issues, help audiences imagine different ways of negotiating their environs or experi-ence a museum in a new way. At times, the bottom floor galleries resembled a theme park – adults and children playing with Legos and using Höller’s slide. This article examines the benefits and limitations of such artistic interventions by relating the GoMA exhibition to Brisbane City Council’s campaign of ‘Together Brisbane’ (featuring images of Neunenschwande’s ribbons); a response to the devastation brought to the city and its surrounds in January 2011. During the Brisbane floods, GoMA’s basement was damaged, the museum closed and upon reopening, visitor numbers soared. In this context, GoMA’s use of engaged art practice – always verging on the ephemeral and ‘fun’ – has been used to project a wider notion of a collective urban public. What questions does this raise, not only regarding the cultural politics around the social and participatory ‘turn’ in art practice, but its use to address a much wider urban public in a moment of crisis.

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Deep inelastic neutron scattering measurements on liquid 3He-4He mixtures in the normal phase have been performed on the VESUVIO spectrometer at the ISIS pulsed neutron source at exchanged wave vectors of about q≃120.0Å-1. The neutron Compton profiles J(y) of the mixtures were measured along the T=1.96K isotherm for 3He concentrations, x, ranging from 0.1 to 1.0 at saturated vapor pressures. Values of kinetic energies 〈T〉 of 3He and 4He atoms as a function of x, 〈T〉(x), were extracted from the second moment of J(y). The present determinations of 〈T〉(x) confirm previous experimental findings for both isotopes and, in the case of 3He, a substantial disagreement with theory is found. In particular 〈T〉(x) for the 3He atoms is found to be independent of concentration yielding a value 〈T〉3(x=0.1)≃12K, much lower than the value suggested by the most recent theoretical estimates of approximately 19 K.

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Polymeric graphitic carbon nitride materials have attracted increasing attention in recent years owning to their potential applications in energy conversion, environment protection, and so on. Here, from first-principles calculations, we report the electronic structure modification of graphitic carbon nitride (g-C3N4) in response to carbon doping. We showed that each dopant atom can induce a local magnetic moment of 1.0 μB in non-magnetic g-C3N4. At the doping concentration of 1/14, the local magnetic moments of the most stable doping configuration which has the dopant atom at the center of heptazine unit prefer to align in a parallel way leading to long-range ferromagnetic (FM) ordering. When the joint N atom is replaced by C atom, the system favors an antiferromagnetic (AFM) ordering at unstrained state, but can be tuned to ferromagnetism (FM) by applying biaxial tensile strain. More interestingly, the FM state of the strained system is half-metallic with abundant states at the Fermi level in one spin channel and a band gap of 1.82 eV in another spin channel. The Curie temperature (Tc) was also evaluated using a mean-field theory and Monte Carlo simulations within the Ising model. Such tunable electron spin-polarization and ferromagnetism are quite promising for the applications of graphitic carbon nitride in spintronics.

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The mean action time is the mean of a probability density function that can be interpreted as a critical time, which is a finite estimate of the time taken for the transient solution of a reaction-diffusion equation to effectively reach steady state. For high-variance distributions, the mean action time under-approximates the critical time since it neglects to account for the spread about the mean. We can improve our estimate of the critical time by calculating the higher moments of the probability density function, called the moments of action, which provide additional information regarding the spread about the mean. Existing methods for calculating the nth moment of action require the solution of n nonhomogeneous boundary value problems which can be difficult and tedious to solve exactly. Here we present a simplified approach using Laplace transforms which allows us to calculate the nth moment of action without solving this family of boundary value problems and also without solving for the transient solution of the underlying reaction-diffusion problem. We demonstrate the generality of our method by calculating exact expressions for the moments of action for three problems from the biophysics literature. While the first problem we consider can be solved using existing methods, the second problem, which is readily solved using our approach, is intractable using previous techniques. The third problem illustrates how the Laplace transform approach can be used to study coupled linear reaction-diffusion equations.

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In this paper, we interrogate the way that narratives about the unfolding of settler colonialism through time are encoded in recent Australian Indigenous policy frameworks. We argue that the postcolonial image of a single transformative moment of radical political break is embedded in Australian policy frameworks, but is deployed in ways that fuse this idea with the moment of colonial completion and in so doing assist the colonial project. By merging the moment of decolonisation and the moment of colonial completion, temporal narratives mobilise conservative and progressive settler voices towards colonial goals. We identify three recent policy approaches: reconciliation, neoliberal contractualism and intervention, and interrogate the narratives of the present and future that they reflect and deploy. We argue these unacknowledged stories of the colonial future must be contested, so that debates about how settler and Indigenous people might live together differently across time are not foreclosed.

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Nanomaterials are prone to influence by chemical adsorption because of their large surface to volume ratios. This enables sensitive detection of adsorbed chemical species which, in turn, can tune the property of the host material. Recent studies discovered that single and multi-layer molybdenum disulfide (MoS2) films are ultra-sensitive to several important environmental molecules. Here we report new findings from ab inito calculations that reveal substantially enhanced adsorption of NO and NH3 on strained monolayer MoS2 with significant impact on the properties of the adsorbates and the MoS2 layer. The magnetic moment of adsorbed NO can be tuned between 0 and 1 μB; strain also induces an electronic phase transition between half-metal and metal. Adsorption of NH3 weakens the MoS2 layer considerably, which explains the large discrepancy between the experimentally measured strength and breaking strain of MoS2 films and previous theoretical predictions. On the other hand, adsorption of NO2, CO, and CO2 is insensitive to the strain condition in the MoS2 layer. This contrasting behavior allows sensitive strain engineering of selective chemical adsorption on MoS2 with effective tuning of mechanical, electronic, and magnetic properties. These results suggest new design strategies for constructing MoS2-based ultrahigh-sensitivity nanoscale sensors and electromechanical devices.

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The ion (C6CH2)(.-) is formed in the gas phase by the process -C=C-C=C-C=CH2OEt --> (C6CH2)(.-) + EtO., and charge stripping of the product radical anion yields the carbenoid neutral C6CH2; this can be either a singlet (the ground state), which is best represented as the carbene :C=C=C=C=C=C=CH2, or a triplet; the adiabatic electron affinity and the dipole moment of the carbenoid neutral are calculated to be 2.82 eV and 7.33 D respectively.

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Computations at the RCCSD(T)/aug-cc-pVDZ//B3LYP/6-31G* level of theory indicate that neutral C6CO is a stable species. The ground state of this neutral is the singlet cumulene oxide :C=C=C=C=C=C=C=O. The adiabatic electron affinity and dipole moment of singlet C6CO are 2.47 eV and 4.13 D, respectively, at this level of theory. The anion (C6CO)(-.) should be a possible precursor to this neutral. It has been formed by an unequivocal synthesis in the ion source of a mass spectrometer by the S(N)2(Si) reaction between (CH3)(3)Si-C=C-C=C-C=C-CO-CMe3 and F- to form C-=C-C=C-C=C-CO-CMe3 which loses Me3C in the source to form C6CO-.. Charge stripping of this anion by vertical Franck-Condon oxidation forms C6CO, characterised by the neutralisation-reionisation spectrum (-NR+) of C6CO-., which is stable during the timeframe of this experiment (10(-6) s), Copyright (C) 2000 John Wiley & Sons, Ltd.

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“Hybrid” hydrogen storage, where hydrogen is stored in both the solid material and as a high pressure gas in the void volume of the tank can improve overall system efficiency by up to 50% compared to either compressed hydrogen or solid materials alone. Thermodynamically, high equilibrium hydrogen pressures in metal–hydrogen systems correspond to low enthalpies of hydrogen absorption–desorption. This decreases the calorimetric effects of the hydride formation–decomposition processes which can assist in achieving high rates of heat exchange during hydrogen loading—removing the bottleneck in achieving low charging times and improving overall hydrogen storage efficiency of large hydrogen stores. Two systems with hydrogenation enthalpies close to −20 kJ/mol H2 were studied to investigate the hydrogenation mechanism and kinetics: CeNi5–D2 and ZrFe2−xAlx (x = 0.02; 0.04; 0.20)–D2. The structure of the intermetallics and their hydrides were studied by in situ neutron powder diffraction at pressures up to 1000 bar and complementary X-ray diffraction. The deuteration of the hexagonal CeNi5 intermetallic resulted in CeNi5D6.3 with a volume expansion of 30.1%. Deuterium absorption filled three different types of interstices, Ce2Ni2 and Ni4 tetrahedra, and Ce2Ni3 half-octahedra and was accompanied by a valence change for Ce. Significant hysteresis was observed between deuterium absorption and desorption which profoundly decreased on a second absorption cycle. For the Al-modified Laves-type C15 ZrFe2−xAlx intermetallics, deuteration showed very fast kinetics of H/D exchange and resulted in a volume increase of the FCC unit cells of 23.5% for ZrFe1.98Al0.02D2.9(1). Deuterium content, hysteresis of H/D uptake and release, unit cell expansion and stability of the hydrides systematically change with the amount of Al content. In the deuteride D atoms exclusively occupy the Zr2(Fe,Al)2 tetrahedra. Observed interatomic distances are Zr–D = 1.98–2.11; (Fe, Al)–D = 1.70–1.75A˚ . Hydrogenation slightly increases the magnetic moment of the Fe atoms in ZrFe1.98Al0.02 and ZrFe1.96Al0.04 from 1.9 �B at room temperature for the alloy to 2.2 �B for its deuteride.

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In Christensen v Salter [2002] QDC 082 the District Court of Queensland considered some issues on the limitation period applying to claims arising out of a failed sterilisation procedure

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When preparing this special issue,1 our discussions with the editorial board of the International Journal of Cultural Studies (IJCS) included a moment of simultaneous surprise and reflection, which we would like to use as a starting point for our introduction to the articles appearing here. This occurred during communications about the number and length of the articles required for a special issue. The board’s representative stipulated that a specific number of articles were to be written by Indonesian scholars. The request surprised us. We had neither discussed nor anticipated ethnic or national quotas for authorial participation. But although the request caught us off guard it also stimulated us to think about the two disciplinary terrains traversed in the articles to follow.

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The Lagrangian particle tracking provides an effective method for simulating the deposition of nano- particles as well as micro-particles as it accounts for the particle inertia effect as well as the Brownian excitation. However, using the Lagrangian approach for simulating ultrafine particles has been limited due to computational cost and numerical difficulties. The aim of this paper is to study the deposition of nano-particles in cylindrical tubes under laminar condition using the Lagrangian particle tracking method. The commercial Fluent software is used to simulate the fluid flow in the pipes and to study the deposition and dispersion of nano-particles. Different particle diameters as well as different pipe lengths and flow rates are examined. The results show good agreement between the calculated deposition efficiency and different analytic correlations in the literature. Furthermore, for the nano-particles with higher diameters and when the effect of inertia has a higher importance, the calculated deposition efficiency by the Lagrangian method is less than the analytic correlations based on Eulerian method due to statistical error or the inertia effect.