93 resultados para transition to turbulence
Resumo:
Patients often spend time as inpatients in hospitals outside their home area because of the need to access specialist services. If there is a need for ongoing care after the need for specialist care has passed, patients are transferred (or ‘repatriated’) back to the inpatient care of a hospital in their local Health and Social Care Trust. The need for bed space in specialist units means that there is pressure for this transition to occur in a timely way. We investigated the flow of patients through a trauma and orthopaedics unit using the 6M Design® framework and Vitals Charts® in order to investigate concerns about delayed repatriation. We found that repatriation was part of a complex system that had interdependent components. There was considerable variation in the number of discharges (to any destination) by day of week, with a reduction on Saturdays and Sundays. Understanding that the pressure for quicker repatriation was really due to high work-in-progress led us to model the effects of strategies to address the high work-in-progress. We found that, because only a small proportion of patients require repatriation, expediting the repatriation process by one day for each patient would only reduce WIP by an average of 1.6 patients. Reducing the average length of stay for all trauma and orthopaedics inpatients by one day would reduce the WIP by 10 patients, which would make a much greater impact on the problem of high bed occupancy. Though the smooth and timely repatriation of patients to rehabilitation units is desirable, it is unlikely that efforts to achieve this will have a substantial impact on the problem of high WIP, so other strategies will be required. We will model the effects of strategies to reduce variation in daily discharges by the day of week in a future essay.
Resumo:
An overarching aim of this chapter is to offer an informed and critical analysis of ‘techno-optimism’, informed by an explicitly transdisciplinary approach. A transdisciplinary perspective is one in which knowledge production goes beyond the academy to include end non-academic stakeholders and users. In effect it seeks to ‘upstream’ the involvement of non-academic interests in research design and knowledge production, as opposed to limiting those non-academic interests to the dissemination end point stage of research, which is the dominant research model. Techno-optimism is understood as an exaggerated and unwarranted belief in human technological abilities to solve problems of unsustainability while minimising or denying the need for large-scale social, economic and political transformation. More specifically, techno-optimism is the belief that the negative environmental and social costs of high-consumption, affluent, consumer societies and associated ways of life within capitalist orthodox economic growth orientated socio-economic systems, can be solved or eradicated through technological innovation and breakthroughs. Business as usual can be ‘greened’; a capitalist, growth-based economy can be made more ‘resource efficient’, consumerism less ‘resource intensive’ (and maybe a little bit more ethical). Techno-optimism, to be deliberately provocative for a moment, can therefore be described as a ‘biofuel the hummer’ response to the challenges (and opportunities) of the crisis of unsustainability. What I mean by that analogy is the seductive promise and premise of techno-optimism of not questioning or doubting the status quo (the hummer), hence it’s putative (but entirely false) non-political character. The capitalist, consumerist, growth-based socio-economic system is thus removed from critical analysis (usually on the implicit or explicit assumption of either the normative rightness of this system, or on strategic political grounds that it is naive or utopian to envisage widespread support for a non or post-capitalist consumer system). Techno-optimism simply enables a different means (biofuel) to the same ends.
Resumo:
The transition to a “low carbon, climate resilient and environmentally sustainable economy by the end of the year 2050” has been conceptualised as the “national transition objective” in the Irish Climate Action and Low Carbon Development Bill, passed in late 2015. This has raised a myriad of questions over how this can be operationalised and resourced and whether it can maintain political momentum. This paper assesses the utility of framings informed by the transitions (MLP) and technological innovation systems perspectives in contributing to transformative societal processes, by examining their application in an Irish case study on policy and technology. Through a qualitative exploration of the broader societal and policy context of the energy sector and a more detailed examination of the innovation systems of selected niche technologies (bioenergy and electric vehicles), the Irish case study sought to identify potential catalysts for a sustainability transition in the energy sector in Ireland: where these exist, how these are being built or enabled, and barriers to change. Following a discussion on the theoretical approaches used, a description will be given of how these were applied in the conducting of the research on transition in Ireland case study and the key findings which emerged. A critical reflection will then be made on the utility of these perspectives (as applied) to contribute to broader processes of societal transformation in Ireland.
Resumo:
Rimming flow on the inner surface of a horizontal rotating cylinder is investigated. Using a scale analysis, a theoretical description is obtained for steady-state non-Newtonian flow. Simple lubrication theory is applied since the Reynolds number is small and the liquid film is thin. Since the Deborah number is very small the flow is viscometric. The shear-thinning number, which characterizes the shear-thinning effect, may be small or large. A general constitutive law for this kind of flow requires only a single function relating shear stress and shear rate that corresponds to a generalized Newtonian liquid. For this case the run-off condition for rimming flow is derived. Provided the run-off condition is satisfied, the existence of a continuous steady-state solution is proved. The rheological models, which show Newtonian behavior at low shear rates with transition to power-law shear thinning at moderate shear rates, are considered. Numerical results are carried out for the Carreau and Ellis models, which exhibit Newtonian behavior near the free surface and power-law behavior near the wall of the rotating cylinder.
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Inductively coupled radio-frequency plasmas can be operated in two distinct modes. At low power and comparatively low plasma densities the plasma is sustained in capacitive mode (E-mode). As the plasma density increases a transition to inductive mode (H-mode) is observed. This transition region is of particular interest and governed by non-linear dynamics, which under certain conditions results in structure formation with strong spatial gradients in light emission. These modes show pronounced differences is various measureable quantities e.g. electron densities, electron energy distribution functions, ion energy distribution functions, dynamics of optical light emission. Here the transition from E- to H- mode in an oxygen containing inductively coupled plasma (ICP) is investigated using space and phase resolved optical emission spectroscopy (PROES). The emission, measured phase resolved, allows investigation of the electron dynamics within the rf cycle, important for understanding the power coupling and ionization mechanisms in the discharge. The temporal variation of the emission reflects the dynamics of relatively high-energy electrons. It is possible to distinguish between E- and H-mode from the intensity and temporal behaviour of the emission.
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At a time of increased evaluations of law, human rights, and the rise of judicial power all over the globe, the work of most African judiciaries and the principles of the jurisprudence they espouse in promoting social justice remain an unlikely focus of comparative legal scholarship. This ought not to be so in view of the considerable activities of the courts on the continent in the dawn of the third wave of democratization. This article explores the work of the Nigerian Supreme Court in the political transition to democracy since 1999. Utilizing insights from the work of Ruti Teitel, it attempts to outline some of the major constitutional and extraconstitutional principles adopted by the Court in mediating intergovernmental contestations in the turbulent transition away from almost three decades of authoritarian military rule. It emerges that the task of fostering social transformation through the “weakest” branch seriously tasks the institutional integrity of the judiciary.
Resumo:
Following its transition to democracy from an authoritarian military rule marked by gross violations of human rights, Nigeria established the Human Rights Violations Investigations Commission (HRVIC) in 1999. This paper critically examines the contributions of the HRVIC, popularly known as the ‘Oputa Panel,’ to the field of transitional justice and the rule of law. It sets out the process of establishing the Commission, its mandate and how this mandate was interpreted during the course of the Commission’s work. The challenges faced by the Oputa Panel, particularly those that relate to its legal status and relationship with the judiciary, are analyzed in an attempt to draw useful guidelines from these challenges for other truth commissions. Recourse by powerful individuals to the judicial process in a bid to shield themselves from the HRVIC merits particular review as it raises questions regarding the transformation of the judiciary and the rule of law in the wake of an authoritarian regime.
Resumo:
This article presents a re-conceptualization of moderate adolescent drug use. It is argued that experimentation with alcohol and other drugs during the teenage years may play an important role in the development of regulatory competency in relation to drug consumption in adulthood. When such regulatory skills fail to emerge in young people, during the transition to adulthood, the likelihood of serious alcohol- or drug-related harm is increased. The article reviews the empirical evidence of poor self-regulation as a predictor of long-term alcohol-and drug-related problems, places self-regulation within a broader theoretical framework, and considers the policy and practice implications of this conceptualization.
Resumo:
The making private of hitherto public goods is a central tenet of neoliberalism. From land in Africa, Asia, and South America to the assertion of property rights over genes and cells by corporations, the process(es) of making private property matters more than ever. And yet, despite this importance, we know remarkably little about the spatial plays through which things become private property. In this paper I seek to address this imbalance by focusing upon the formative context of 18th- and early-19th-century England. The specific lens is wood, that most critical of all ‘natural’ things other than land in the transition to market-driven economies. It is shown that the interplay between custom, law, and local practices rendered stable and aspatial definitions of property impossible. Whilst law was the key technology through which property was mediated, the cadence of particular places gave these mediations distinctive forms. I conclude that not only must we take property seriously, but we must also take the conditions and contexts of its making seriously too.
Resumo:
Bone void fillers that can enhance biological function to augment skeletal repair have significant therapeutic potential in bone replacement surgery. This work focuses on the development of a unique microporous (0.5-10 mu m) marine-derived calcium phosphate bioceramic granule. It was prepared fro Corallina officinalis, a mineralized red alga, using a novel manufacturing process. This involved thermal processing, followed by a low pressure-temperature chemical synthesis reaction. The study found that the ability to maintain the unique algal morphology was dependent on the thermal processing conditions. This study investigates the effect of thermal heat treatment on the physiochemical properties of the alga. Thermogravimetric analysis was used to monitor its thermal decomposition. The resultant thermograms indicated the presence of a residual organic phase at temperatures below 500 degrees C and an irreversible solid-state phase transition from mg-rich-calcite to calcium oxide at temperatures over 850 degrees C. Algae and synthetic calcite were evaluated following heat treatment in an air-circulating furance at temperatures ranging from 400 to 800 degrees C. The highest levels of mass loss occurred between 400-500 degrees C and 700-800 degrees C, which were attributed to the organic and carbonate decomposition respectively. The changes in mechanical strength were quantified using a simple mechanical test, which measured the bulk compressive strength of the algae. The mechanical test used may provide a useful evaluation of the compressive properties of similar bone void fillers that are in granular form. The study concluded that soak temperatures in the range of 600 to 700 degrees C provided the optimum physiochemical properties as a precursor to conversion to hydroxyapatite (HA). At these temperatures, a partial phase transition to calcium oxide occurred and the original skeletal morphology of the alga remained intact.
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This paper looks at urban regeneration in Belfast as a stage on which the interaction between different structural dynamics (political, economic and cultural) is manifested in the city. It discusses how contested ideas of ‘space’, ‘place’ and ‘territory’ frame the ways in which Belfast has changed over recent years and asks if regeneration itself has the potential to transform the dynamic of deep-rooted ethno-national divisions. The research question is explored through a case study of proposed urban regeneration in north Belfast. It is found that, while there is evidence of transition to less exclusivistic attitudes in leisure and work spaces, asymmetrical conflict over residential space persists in ways which reproduce deep-rooted political and cultural patterns of territorial fixity and division.
Resumo:
A supported ionic liquid phase (SILP) catalyst prepared from [PrMIM][Ph2P(3-C6H4SO3)] (PrMIM = 1-propyl-3-methylimidazolium), [Rh(CO)(2)(acac)] (acacH = 2,4-pentanedione) [OctMIM]NTf2 (OctMIM = 1-n-octyl-3-methylimidazolium, Tf = CF3SO2) and microporous silica has been used for the continuous flow hydroformylation of 1-octene in the presence of compressed CO2. Statistical experimental design was used to show that the reaction rate is neither much affected by the film thickness (IL loading) nor by the syngas: substrate ratio. However, a factor-dependent interaction between the syngas: substrate ratio and film thickness on the reaction rate was revealed. Increasing the substrate flow led to increased reaction rates but lower overall yields. One of the most important parameters proved to be the phase behaviour of the mobile phase, which was studied by varying the reaction pressure. At low CO2 pressures or when N-2 was used instead of CO2 rates were low because of poor gas diffusion to the catalytic sites in the SILP. Furthermore, leaching of IL and Rh was high because the substrate is liquid and the IL had been designed to dissolve in it. As the CO2 pressure was increased, the reaction rate increased and the IL and Rh leaching were reduced, because an expanded liquid phase developed. Due to its lower viscosity the expanded liquid allows better transport of gases to the catalyst and is a poorer solvent for the IL and the catalyst because of its reduced polarity. Above 100 bar (close to the transition to a single phase at 106 bar), the rate of reaction dropped again with increasing pressure because the flowing phase becomes a better and better solvent for the alkene, reducing its partitioning into the IL film. Under optimised conditions, the catalyst was shown to be stable over at least 40 h of continuous catalysis with a steady state turnover frequency (TOF, mol product (mol Rh)(-1)) of 500 h(-1) at low Rh leaching (0.2 ppm). The selectivity of the catalyst was not much affected by the variation of process parameters. The linear: branched (1:b) ratios were ca. 3, similar to that obtained using the very same catalyst in conventional organic solvents.
Resumo:
Durkheim’s idea that war reduces suicide through greater social and political integration has been used to explain suicide trends during the Northern Ireland conflict and in the period of peace. The applicability of Durkheim is critically evaluated through a case study of suicide trends by age, gender and cause of death over a forty year period. The key finding is that the cohort of children and young people who grew up in the worst years of violence during the 1970s, have the highest and most rapidly increasing suicide rates, and account for the steep upward trend in suicide following the 1998 Agreement. Contrary to Durkheim, the recent rise in suicide involves a complex of social and psychological factors. These include the growth in social isolation, poor mental health arising from the experience of conflict, and the greater political stability of the past decade. The transition to peace means that externalised aggression is no longer socially approved. It becomes internalised instead.
Resumo:
A chain of singly charged particles, confined by a harmonic potential, exhibits a sudden transition to a zigzag configuration when the radial potential reaches a critical value, depending on the particle number. This structural change is a phase transition of second order, whose order parameter is the crystal displacement from the chain axis. We study analytically the transition using Landau theory and find full agreement with numerical predictions by Schiffer [Phys. Rev. Lett. 70, 818 (1993)] and Piacente [Phys. Rev. B 69, 045324 (2004)]. Our theory allows us to determine analytically the system's behavior at the transition point.
Resumo:
We show that the statistical properties of a Coulomb crystal can be measured by means of a standard interferometric procedure performed on the spin of one ion in the chain. The ion spin, constituted by two internal levels of the ion, couples to the crystal modes via spatial displacement induced by photon absorption. The loss of contrast in the interferometric signal allows one to measure the autocorrelation function of the crystal observables. Close to the critical point, where the chain undergoes a second-order phase transition to a zigzag structure, the signal gives the behavior of the correlation function at the critical point.