997 resultados para Decomposition framework
Resumo:
Selected silicas were modified with the covalently bound ligand 2,6-bis(benzoxazoyl)pyridine (BBOP), equilibrated with copper(II) nitrate, then challenged with toxic vapour containing HCN (8000 mg m(-3) at 80% relative humidity). The modified SBA-15 material (Cu-BBOP-SBA-15) had an improved breakthrough time for HCN (36 min at a flow rate of 30 cm(3) min(-1)) when compared to the other siliceous materials prepared in this study, equating to a hydrogen cyanide capacity of 58 mg g(-1), which is close to a reference activated carbon adsorbent (24 min at 50 cm(3) min(-1)) that can trap 64 mg g(-1). The enhanced performance observed with Cu-BBOP-SBA-15 has been related to the greater accessibility of the functional groups, arising from the ordered nature of the interconnected porous network and large mesopores of 5.5 nm within the material modified with the Cu(II)-BBOP complex. Modified MCM-41 and MCM-48 materials (Cu-BBOP-MCM-41 and Cu-BBOP-MCM-48) were found to have lower hydrogen cyanide capacities (38 and 32 mg g(-1) respectively) than the Cu-BBOP-SBA-15 material owing to the restricted size of the pores (2.2 and <2 nm respectively). The materials with poor nano-structured ordering were found to have low hydrogen cyanide capacities, between 11 and 19 mg g(-1), most likely owing to limited accessibility of the functional groups. (C) 2004 Elsevier Inc. All rights reserved.
Resumo:
The kinetics of the title reactions have been studied by relative-rate methods as a function of temperature. Relative-rate coefficients for the two decomposition channels of 2-methyl-2-butoxyl have been measured at five different temperatures between 283 and 345 K and the observed temperature dependence is consistent with the results of some previous experimental studies. The kinetics of the two decomposition channels of 2-methyl-2-pentoxyl have also been investigated, as a function of temperature, relative to the estimated rate of isomerisation of this radical. Room-temperature rate coefficient data for the two decomposition channels of both 2-methyl-2-pentoxyl and 2-methyl-2-butxoyl (after combining the relative rate coefficient for this latter with a value for the rate coefficient of the major channel, extrapolated from the data presented by Batt et al., Int. J. Chem. Kinet., 1978, 10, 931) are shown to be consistent with a non-linear kinetic correlation, for alkoxyl radical decomposition rate data, previously presented by this laboratory (Johnson et al., Atmos. Environ., 2004, 38, 1755-1765).
Resumo:
In the reaction of equimolar amounts of copper(II) acetate with 2,2'-dipyridylamine (DPA) in aqueous tetrahydrofuran, in presence of KOH, aerial CO2 is spontaneously fixed to the carbonate anion yielding [Cu(DPA)(CO3)] . 3H(2)O (1). X-ray crystallography shows the presence of zigzag ribbons of cyclic water pentamers in the channels of a chain-like metallo-organic framework. The water ribbons are stabilised by hydrogen bonds to the metallo-organic backbone. Each (H2O)(5) pentamer is approximately planar.
Resumo:
The built environment in which health and social care is delivered can have an impact on the efficiency and outcomes of care processes. The health-care estate is large and growing and is expensive to build, adapt and maintain. The design of these buildings is a complex, difficult and political process. Better use of care pathways as an input to the design and use of the built environment has the potential to deliver significant benefits. A number of variations on the idea of care pathways are already used in designing health-care buildings but this is under-researched. This paper provides a framework for thinking about care pathways and the health-care built environment. The framework distinguishes between five different pathway ‘types’ defined for the purpose of understanding the relationship between pathways and infrastructure. The five types are: ‘care pathways’, ‘integrated care pathways’, ‘patient pathways’, ‘patient journeys’ and ‘patient flows’. The built environment implications of each type are discussed and recommendations made for those involved in either building development or care pathway projects.
Resumo:
The built environment in which health and social care is delivered can have an impact on the efficiency and outcomes of care processes. The health-care estate is large and growing and is expensive to build, adapt and maintain. The design of these buildings is a complex, difficult and political process. Better use of care pathways as an input to the design and use of the built environment has the potential to deliver significant benefits. A number of variations on the idea of care pathways are already used in designing health-care buildings but this is under-researched. This paper provides a framework for thinking about care pathways and the health-care built environment. The framework distinguishes between five different pathway ‘types’ defined for the purpose of understanding the relationship between pathways and infrastructure. The five types are: ‘care pathways’, ‘integrated care pathways’, ‘patient pathways’, ‘patient journeys’ and ‘patient flows’. The built environment implications of each type are discussed and recommendations made for those involved in either building development or care pathway projects.
Resumo:
The UK Construction Industry has been criticized for being slow to change and adopt innovations. The idiosyncrasies of participants, their roles in a social system and the contextual differences between sections of the UK Construction Industry are viewed as being paramount to explaining innovation diffusion within this context. Three innovation diffusion theories from outside construction management literature are introduced, Cohesion, Structural Equivalence and Thresholds. The relevance of each theory, in relation to the UK Construction Industry, is critically reviewed using literature and empirical data. Analysis of the data results in an explanatory framework being proposed. The framework introduces a Personal Awareness Threshold concept, highlights the dominant role of Cohesion through the main stages of diffusion, together with the use of Structural Equivalence during the later stages of diffusion and the importance of Adoption Threshold levels.