647 resultados para Speculative bubbles
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The second or speculative portion was published as a distinct work, entitled, Grundzüge zum Systeme der Philosophie.
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Dedication dated Dublin, July 15, 1781.
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On t.-p. of v. 7: 1843-79.
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Aphrodite, the kittiwake.--Margot, the crow shrike.--"Petey.--Two gentleman of France--Julius Caesar; an appreciation.--A hermit crab of the Great Kills.--Silas Wegg.--the wife of Caesar, the adjutant.--"Bubbles." Madame Cistudo.--Lena Patéa.--The passing of Maud Mulvaney.
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(cont.) [v.8]. Wild oats; Serious family; Paul Pry; Charles II; Game of Love; Queen Mary's bower; Andy Blake; Naval engagements; Rochester; Artist's wife; Delicate ground; Two queens; Damon and Pythias; Rose of Arragon; Charles I; Mary Stuart; Love's frailties; Fanchon, the cricket; Lear of private life; Robert Macaire.
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Considering the importance of the proper detection of bubbles in financial markets for policymakers and market agents, we used two techniques described in Diba and Grossman (1988b) and in Phillips, Shi, and Yu (2015) to detect periods of exuberance in the recent history of the Brazillian stock market. First, a simple cointegration test is applied. Secondly, we conducted several augmented, right-tailed Dickey-Fuller tests on rolling windows of data to determine the point in which there’s a structural break and the series loses its stationarity.
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Thesis (Ph.D.)--University of Washington, 2016-06
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his paper analyzes the discursive construction and contestation of ‘leaked’ stories in news broadcast programmes. Drawing on a sample of BBC Radio 4 news programmes recorded between May and June 2000, we analyze four items of news presented as leaks about upcoming events. We suggest that these examples highlight the leaking of information as a valuable newsworthy commodity in that it not only allows news organizations to report what is going to be news before it happens but also enables speculative discourse as to the meaning of the event yet to happen. However, in order for a story to be accepted as a leak it must be seen to fulfil a number of criteria. With this in mind, we identify four features accompanying the introduction of the news items as leaks in the process of authentification: secrecy, authorship/ownership and future orientation. The article then discusses how these features are used when contesting the status of a news story as a leak, and how temporal play contributes to downgrading the content of the leak and, hence, its relevance, immediacy and newsworthiness.
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Objectives: To identify and demonstrate necrotizing dermatitis in infancy; an uncommon, puzzling syndrome, in which anecdotal reporting and personal experience indicates that one third of cases may require skin grafting. Much informed discussion about the pathogenesis of this distressing syndrome centres on the role of spider envenomation; and in particular on the speculative role of the Australian White-tailed spider, Lampona cylindrata. Methods: We present here six cases of necrotizing dermatitis treated surgically at the Royal Children's Hospital and Mater Children's Hospital in Brisbane over the period from 1991 to 1999. Clinical history, surgical details and pathological investigations were reviewed in each case. Microbiological investigation of necrotic ulcers included standard aerobic and anaerobic culture. Result: Nocardia and Staphylococcus were cultured in two cases, but no positive bites were witnessed and no spiders were identified by either the children or their parents. All cases were treated with silver sulphadiazine creme. Two of the infants required general anaesthesia, excision debridement and split skin grafting. The White-tailed spider, Lampona cylindrata, does not occur in Queensland, but Lampona murina does; neither species has necrotizing components in its venom. Circumstantial evidence is consistent with this syndrome being due to invertebrate envenomation, possibly following arachnid bites. Conclusion: In our experience there is insufficient evidence to impute a specific genus as the cause, at this stage of scientific knowledge. If the offending creature is a spider, we calculate that the syndrome of necrotizing dermatitis occurs in less than 1 in 5000 spider bites.
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Froth recovery measurements have been conducted in both the presence (three-phase froth) and absence (two-phase froth) of particles of different contact angles in a specially modified laboratory flotation column. Increasing the particle hydrophobicity increased the flow rate of particles entering the froth, while the recovery of particles across the froth phase itself also increased for particle contact angles to 63 and at all vertical heights of the froth column. However, a further increase in the contact angle to 69 resulted in lower particle recovery across the froth phase. The reduced froth recovery for particles of 69 contact angle was linked to significant bubble coalescence within the froth phase. The reduced froth recovery occurred uniformly across the entire particle size range, and was, presumably, a result of particle detachment from coalescing bubbles. Water flow rates across the froth phase also varied with particle contact angle. The general trend was a decrease in the concentrate flow rate of water with increasing particle contact angle. An inverse relationship between water flow rate and bubble radius was also observed, possibly allowing prediction of water flow rate from bubble size measurements in the froth. Comparison of the froth structure, defined by bubble size, gas hold-up and bubble layer thickness, for two- and three-phase froths, at the same frother concentration, showed there was a relationship between water flow rate and froth structure. (c) 2005 Elsevier B.V. All rights reserved.
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The problem of asset price bubbles, and more generally of instability in the financial system, has been a matter of concern since the 1980s but has only recently moved to the center of the macroeconomic policy debate. The main concern with bubbles arises when they burst, imposing losses on investors holding the bubble assets and potentially on the financial institutions that have extended credit to them. Asset price volatility is an inevitable consequence of financial market liberalization and, in extreme cases, generates asset price bubbles, the bursting of which can impose substantial economic and social costs. Policy responses within the existing liberalized financial system face daunting levels of uncertainty and risk. Given the pattern of increasing asset market volatility over recent decades and the policy issues highlighted in this paper, the future looks uncertain. Another significant cycle of asset price movements, especially in one of the major economies, could see a fundamental revision of thinking about the costs and benefits of liberalized financial systems.
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In this paper we use computational fluid dynamics (CFD) to study the effect of contact angle on droplet shape as it moves through a contraction. A new non-dimensional number is proposed in order to predict situations where the deformed droplet will form a slug in the contraction and thus have the opportunity to interact with the channel wall. It is proposed that droplet flow into a contraction is a useful method to ensure that a droplet will wet a channel surface without a trapped lubrication film, and thus help ensure that a slug will remain attached to the wall downstream of the contraction. We demonstrate that when a droplet is larger than a contraction, capillary and Reynolds numbers, and fluid properties may not be sufficient to fully describe the droplet dynamics through a contraction. We show that, with everything else constant, droplet shape and breakup can be controlled simply by changing the wetting properties of the channel wall. CFD simulations with contact angles ranging from 30 degrees to 150 degrees show that lower contact angles can induce droplet breakup while higher contact angles can form slugs with contact angle dependent shape. Crown Copyright (c) 2005 Published by Elsevier Inc. All rights reserved.
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Water recovery is one of the key parameters in flotation modelling for the purposes of plant design and process control, as it determines the circulating flow and residence time in the individual process units in the plant and has a significant effect on entrainment and froth recovery. This paper reviews some of the water recovery models available in the literature, including both empirical and fundamental models. The selected models are tested using the data obtained from the experimental work conducted in an Outokumpu 3 m(3) tank cell at the Xstrata Mt Isa copper concentrator. It is found that all the models fit the experimental data reasonably well for a given flotation system. However, the empirical models are either unable to distinguish the effect of different cell operating conditions or required to determine the empirical model parameters to be derived in an existing flotation system. The model developed by [Neethling, SJ., Lee, H.T., Cilliers, J.J., 2003, Simple relationships for predicting the recovery of liquid from flowing foams and froths. Minerals Engineering 16, 1123-1130] is based on fundamental understanding of the froth structure and transfer of the water in the froth. It describes the water recovery as a function of the cell operating conditions and the froth properties which can all be determined on-line. Hence, the fundamental model can be used for process control purposes in practice. By incorporating additional models to relate the air recovery and surface bubble size directly to the cell operating conditions, the fundamental model can also be used for prediction purposes. (C) 2005 Elsevier Ltd. All rights reserved.
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For nearly 100 years, the flotation plant metallurgist has often wondered what is happening 'beneath the froth'. To assist in unravelling this mystery, new technology has been developed as part of the Australian Mineral Industries Research Association (AMIRA) P9 project, to measure gas dispersion characteristics (such as gas hold-up, superficial gas velocity and bubble size) in industrial flotation cells. These measurements have been conducted in a large number of cells of different types and sizes by researchers from the Julius Kruttschnitt Mineral Research Centre (JKMRC) and JKTech. A large database has been developed and the contents of this database are described in this paper. Typical cell characterization measurements show a wide spread in values, even in the same cell types and sizes performing similar duties. In conventional flotation cells, the typical gas hold-up values range from 3% to 20%, bubble sizes range between I and 2 mm, and superficial gas velocity ranges from 1 to 2.5 cm/s. The ranges of cell characterization measurements given in this paper will enable plant personnel to compare their operation to other similar types of operations from around Australia and the rest of the world, giving opportunities for further improvement to flotation plant operations. (C) 2005 Elsevier Ltd. All rights reserved.
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The Jameson Cell is a high intensity flotation device, which utilises induced air from the atmosphere. It was developed jointly by Mount Isa Mines and Professor Graeme Jameson of the University of Newcastle in the 1980s. It is proven to generate fine bubbles, in the order of 300 to 500 µm, in a high intensity, high shear and compact zone contained in the downcomer. This aerated mixture exits the downcomer into the pulp zone, which is the quiescent mineral and gangue separation zone. A number of Australian base metal flotation circuits feature a reverse flotation stage at the head of the circuit. Testwork and plant operating data has shown that the use of a Jameson Cell in the prefloat cleaner application has further improved prefloat gangue recovery and selectivity. Operation of a Jameson Cell in a carbonaceous/pyrite prefloat cleaner duty at the Mt Isa copper concentrator increased copper recovery and reduced pyrite in the copper concentrate. Testwork at Zinifex Century Zinc Mine showed a decrease in zinc losses by the utilisation of Jameson Cell prefloat cleaner. Appraisal of a Jameson Cell in a scalping role within the Mt Isa Copper Concentrator indicated significant benefits could be achieved.