990 resultados para 7039-103
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Servicios registrales
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Servicios registrales
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The thermal behaviour of halloysite fully expanded with hydrazine-hydrate has been investigated in nitrogen atmosphere under dynamic heating and at a constant, pre-set decomposition rate of 0.15 mg min-1. Under controlled-rate thermal analysis (CRTA) conditions it was possible to resolve the closely overlapping decomposition stages and to distinguish between adsorbed and bonded reagent. Three types of bonded reagent could be identified. The loosely bonded reagent amounting to 0.20 mol hydrazine-hydrate per mol inner surface hydroxyl is connected to the internal and external surfaces of the expanded mineral and is present as a space filler between the sheets of the delaminated mineral. The strongly bonded (intercalated) hydrazine-hydrate is connected to the kaolinite inner surface OH groups by the formation of hydrogen bonds. Based on the thermoanalytical results two different types of bonded reagent could be distinguished in the complex. Type 1 reagent (approx. 0.06 mol hydrazine-hydrate/mol inner surface OH) is liberated between 77 and 103°C. Type 2 reagent is lost between 103 and 227°C, corresponding to a quantity of 0.36 mol hydrazine/mol inner surface OH. When heating the complex to 77°C under CRTA conditions a new reflection appears in the XRD pattern with a d-value of 9.6 Å, in addition to the 10.2 Ĺ reflection. This new reflection disappears in contact with moist air and the complex re-expands to the original d-value of 10.2 Å in a few h. The appearance of the 9.6 Å reflection is interpreted as the expansion of kaolinite with hydrazine alone, while the 10.2 Å one is due to expansion with hydrazine-hydrate. FTIR (DRIFT) spectroscopic results showed that the treated mineral after intercalation/deintercalation and heat treatment to 300°C is slightly more ordered than the original (untreated) clay.
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This paper provides a fresh analysis of the widely-used Common Scrambling Algorithm Stream Cipher (CSA-SC). Firstly, a new representation of CSA-SC with a state size of only 89 bits is given, a significant reduction from the 103 bit state of a previous CSA-SC representation. Analysis of this 89-bit representation demonstrates that the basis of a previous guess-and-determine attack is flawed. Correcting this flaw increases the complexity of that attack so that it is worse than exhaustive key search. Although that attack is not feasible, the reduced state size of our representation makes it obvious that CSA-SC is vulnerable to several generic attacks, for which feasible parameters are given.
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The Architecture, Disciplinarity and the Arts symposium was organised by the Architecture. Theory, Criticism and History (ATCH) research group at the University of Queensland, run by John Macarthur and Antony Moulis, together with Andrew Leach who joined them last year and organised much of the symposium. The symposium ran for three days in a small room at the Institute of Modern Art (IMA) in Fortitude Valley, Brisbane (generously donated by director Robert Leonard), with about 40 people in attendance. Together with a long question time of an hour after every three speakers, the size of the room and the small number of people made it very different from most architecture or design conferences. The intellectual level of the symposium was high, without the speed dating aspect that one often sees at the Society of Architectural Historians, Australia and New Zealand (SAHANZ) meetings, where endless parallel sessions of short papers create an occasionally disorientating cacophony of words. The symposium was deliberately, unapologetically academic and the intimate nature of the forum made the discussion rich and collaborative, with an active audience. The title of the symposium, 'Architecture, Disciplinarity and the Arts', reflects the connection that already exists between the art history and the architectural history community in Brisbane, with both groups regularly attending each other's functions.
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Set atop a magnificent site on the Bellarine Peninsula, Contour House anchors itself into the landscape with a 5.5 meter-high folding concrete wall. This gesture is both protective and revealing, simultaneously creating an internal courtyard, while extending the spectacular 270- degree views into the living areas. This residence extends our interest in 'the journey' and ideas of place-making, particularly the manner in which it might challenge preconceived ways of living.
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Sustainable natural resource management has been a concern of governments and legislators for the last 20 years. A key aspect of an effective management framework is easy access to information about rights and obligations in land and the natural resources in, on or below the land. Information about legal interests in land is managed through a Torrens register in each Australian State. These registers are primarily focused on the registration of a narrow group of legal interests in the land, and rights or obligations that fall outside of these recognised interests are not capable of registration. Practices have developed however for the recording of property rights in natural resources either on separate registers, with no link to the Torrens register or on a separate register managed by the Registrar of Titles but having no legal effect on the title to the land. This paper will discuss and analyse the various ways in which registers have been used in Queensland to provide access to information about rights in natural resources, and provide examples as to how this approach has impacted on the desire for sustainable management. It will also provide a critique of the Queensland model, and call for reform of the present system.