951 resultados para mixed monotone property
Resumo:
A series of bimetallic ruthenium complexes [{Ru(dppe)Cp*}2(μ-C≡CArC≡C)] featuring diethynylaromatic bridging ligands (Ar = 1,4-phenylene, 1,4-naphthylene, 9,10-anthrylene) have been prepared and some representative molecular structures determined. A combination of UV–vis–NIR and IR spectroelectrochemical methods and density functional theory (DFT) have been used to demonstrate that one-electron oxidation of compounds [{Ru(dppe)Cp*}2(μ-C≡CArC≡C)](HC≡CArC≡CH = 1,4-diethynylbenzene; 1,4-diethynyl-2,5-dimethoxybenzene; 1,4-diethynylnaphthalene; 9,10-diethynylanthracene) yields solutions containing radical cations that exhibit characteristics of both oxidation of the diethynylaromatic portion of the bridge, and a mixed-valence state. The simultaneous population of bridge-oxidized and mixed-valence states is likely related to a number of factors, including orientation of the plane of the aromatic portion of the bridging ligand with respect to the metal d-orbitals of appropriate π-symmetry.
Resumo:
Tourism is the worlds largest employer, accounting for 10% of jobs worldwide (WTO, 1999). There are over 30,000 protected areas around the world, covering about 10% of the land surface(IUCN, 2002). Protected area management is moving towards a more integrated form of management, which recognises the social and economic needs of the worlds finest areas and seeks to provide long term income streams and support social cohesion through active but sustainable use of resources. Ecotourism - 'responsible travel to natural areas that conserves the environment and improves the well- being of local people' (The Ecotourism Society, 1991) - is often cited as a panacea for incorporating the principles of sustainable development in protected area management. However, few examples exist worldwide to substantiate this claim. In reality, ecotourism struggles to provide social and economic empowerment locally and fails to secure proper protection of the local and global environment. Current analysis of ecotourism provides a useful checklist of interconnected principles for more successful initiatives, but no overall framework of analysis or theory. This paper argues that applying common property theory to the application of ecotourism can help to establish more rigorous, multi-layered analysis that identifies the institutional demands of community based ecotourism (CBE). The paper draws on existing literature on ecotourism and several new case studies from developed and developing countries around the world. It focuses on the governance of CBE initiatives, particularly the interaction between local stakeholders and government and the role that third party non-governmental organisations can play in brokering appropriate institutional arrangements. The paper concludes by offering future research directions."
Resumo:
This paper examines cyclical behaviour in commercial property values over the period 1956 to 1996, using a structural times series (unobserved components) approach. The influence of the transition to short rent reviews during the late 1960s and the short and long-term impacts of the 1974 and 1990 property crashes are also incorporated into the analysis, via dummy variables. It is found that once these variables are taken into account a fairly regular cyclical pattern can be discerned, with a period of about 7.8 years. Furthermore, the 1974 and 1990 property crashes are shown to have had a major long-term impact on property value growth (presumably via their influence on investors' expectations).
Resumo:
Opportunistic land encroachment occurs in many low-income countries, gradually yet pervasively, until discrete areas of common land disappear. This paper, motivated by field observations in Karnataka, India, demonstrates that such an evolution of property rights from common to private may be efficient when the boundaries between common and private land are poorly defined, or ‘‘fuzzy.’’ Using a multi-period optimization model, and introducing the concept of stock and flow enforcement, I show how effectiveness of enforcement effort, whether encroachment is reversible, and punitive fines, influence whether an area of common land is fully defined and protected or gradually or rapidly encroached.
Resumo:
Scintillometry is an established technique for determining large areal average sensible heat fluxes. The scintillometer measurement is related to sensible heat flux via Monin–Obukhov similarity theory, which was developed for ideal homogeneous land surfaces. In this study it is shown that judicious application of scintillometry over heterogeneous mixed agriculture on undulating topography yields valid results when compared to eddy covariance (EC). A large aperture scintillometer (LAS) over a 2.4 km path was compared with four EC stations measuring sensible (H) and latent (LvE) heat fluxes over different vegetation (cereals and grass) which when aggregated were representative of the LAS source area. The partitioning of available energy into H and LvE varied strongly for different vegetation types, with H varying by a factor of three between senesced winter wheat and grass pasture. The LAS derived H agrees (one-to-one within the experimental uncertainty) with H aggregated from EC with a high coefficient of determination of 0.94. Chronological analysis shows individual fields may have a varying contribution to the areal average sensible heat flux on short (weekly) time scales due to phenological development and changing soil moisture conditions. Using spatially aggregated measurements of net radiation and soil heat flux with H from the LAS, the areal averaged latent heat flux (LvELAS) was calculated as the residual of the surface energy balance. The regression of LvELAS against aggregated LvE from the EC stations has a slope of 0.94, close to ideal, and demonstrates that this is an accurate method for the landscape-scale estimation of evaporation over heterogeneous complex topography.
Resumo:
A series of copolymers containing differing proportions of pyrrole and N-methyl pyrrole were prepared electrochemically at various temperatures using acetonitrile as the solvent. The resultant electrical conductivity decreases universally with increasing fraction of N-methyl pyrrole. Films prepared with p-toluene sulfonate as the dopant show a marked variation in structural anisotropy as revealed by X-ray scattering with apparent copolymer content. There is a clear trend between the variation in electrical conductivity and this structural anisotropy. Different patterns of behaviour are observed for films prepared using perchlorate as the dopant and this is attributed to the role of the dopant and final structure in determining the relative reactivities of the pyrrole and N-methyl pyrrole monomers. These observations support the concept that the introduction of methyl substituents into a polypyrrole chain results in a twisted chain conformation. The structure and properties of the resultant copolymer films are particularly sensitive to the preparation conditions.
Resumo:
Fermentation properties of oligosaccharides derived from lactulose (OsLu) and lactose (GOS) have been assessed in pH-controlled anaerobic batch cultures using lactulose and Vivinal-GOS as reference carbohydrates. Changes in gut bacterial populations and their metabolic activities were monitored over 24 h by fluorescent in situ hybridization (FISH) and by measurement of short-chain fatty acid (SCFA) production. Lactulose-derived oligosaccharides were selectively fermented by Bifidobacterium and lactic acid bacterial populations producing higher SCFA concentrations compared to GOS. The highest total SCFA production was from Vivinal-GOS > lactulose > OsLu > GOS. Longer incubation periods produced a selective fermentation of OsLu when they were used as a carbon source reaching the highest selective index scores. The new oligosaccharides may constitute a good alternative to lactulose, and they could belong to a new generation of prebiotics to be used as a functional ingredient for improving the composition of gut microflora.
Resumo:
This paper identifies some significant gaps in our knowledge of the configuration and performance of the property asset management sector. It is argued that, as many leading academic property researchers have focussed on financial vehicles and modelling, in-depth analysis of property assets and their management has been neglected. In terms of potential for future in-depth research, three key broad preliminary research themes or questions are identified. First, how do the active management opportunities presented, costs of management and the key management tasks vary with market conditions, asset type and life-cycle stage? Second, how is property asset management delivered and what are the main costs and benefits of different models of procurement? Finally, what are the appropriate metrics for measuring the performance of different property managers and approaches to property management? It is concluded that the lack of published materials addressing these issues has implications for educating property students.
Resumo:
This study describes the turbulent processes in the upper ocean boundary layer forced by a constant surface stress in the absence of the Coriolis force using large-eddy simulation. The boundary layer that develops has a two-layer structure, a well-mixed layer above a stratified shear layer. The depth of the mixed layer is approximately constant, whereas the depth of the shear layer increases with time. The turbulent momentum flux varies approximately linearly from the surface to the base of the shear layer. There is a maximum in the production of turbulence through shear at the base of the mixed layer. The magnitude of the shear production increases with time. The increase is mainly a result of the increase in the turbulent momentum flux at the base of the mixed layer due to the increase in the depth of the boundary layer. The length scale for the shear turbulence is the boundary layer depth. A simple scaling is proposed for the magnitude of the shear production that depends on the surface forcing and the average mixed layer current. The scaling can be interpreted in terms of the divergence of a mean kinetic energy flux. A simple bulk model of the boundary layer is developed to obtain equations describing the variation of the mixed layer and boundary layer depths with time. The model shows that the rate at which the boundary layer deepens does not depend on the stratification of the thermocline. The bulk model shows that the variation in the mixed layer depth is small as long as the surface buoyancy flux is small.
Resumo:
In the context of the financial crash and the commercial property market downturn, this paper examines the basis of valuation used in the UK commercial property lending process. Post-crisis there is discussion of countercyclical measures including the monitoring of asset prices; however there is no consideration of a different approach to property valuation. This paper questions this omission, given the role that valuations play in the bank regulatory process. The different bases of valuation available to lenders within International Valuation Standards are identified as Market Value (MV), Mortgage Lending Value (MLV) and Investment Value (IV), with MV being the most used in the UK. Using the different bases in the period before the financial crisis, the UK property market is modelled at a national office, retail and industrial/warehouse sector level to determine the performance of each alternative valuation basis within the context of counter-cyclical pressures on lending. Both MLV and IV would have produced lower valuations and could have provided lenders with tools for more informed and prudent lending. The paper concludes by recognising some of the practical issues involved in adopting the different bases for the bank lending role but recommends a change to IV.
Resumo:
This paper focuses on the effect of energy performance ratings on the capital values, rental values and equivalent yields of UK commercial property assets. Of which a small number are also BREEAM rated, the study is based upon 708 commercial property assets held in the IPD UK Universe drawn from across all PAS segments. Incorporating a range of controls such as unexpired lease term, vacancy rate and tenant credit risk, hedonic regression procedures are used to estimate the effect of EPC rating. The study finds no evidence of a strong relationship between environmental and/or energy performance and rental and capital value. Bearing in mind the small number of BREEAM rated assets, there was a small but statistically significant effect on equivalent yield only. Similarly, there was no evidence that the EPC rating had any effect on Market Rent or Market Value with only minor effects of EPC ratings on equivalent yields. The preliminary conclusion is that energy labelling is not yet having the effects on Market Values and Market Rents that provide incentives for market participants to improve the energy efficiency of their commercial real estate assets.
Resumo:
The terms of a commercial property lease covers aspects such as rent, alterations to premises and the ability to leave; consequently they have a significant impact on cash flow and the ability of a business to develop. In contrast to the heavily-legislated residential sector, commercial landlords and tenants in the UK are largely free to negotiate the terms of their contract. Yet, since the property crash of 1989/90, successive governments have taken an interest in commercial leasing; in particular there is a desire to see landlords being more flexible. UK Government policy in this area has been pursued through industry self-regulation rather than legislation; since 1995 there have been three industry codes of practice on leasing. These codes are sanctioned by government and monitored by them. Yet, 15 years after the first code was launched, many in the industry see the whole code concept as ineffective and unlikely to ever achieve changes to certain aspects of landlord behaviour. This paper is the first step in considering the lease codes in the wider context of industry self-regulation. The aim of the paper is twofold: First a framework is created using the literature on industry self-regulation from various countries and industries which suggests key criteria to explain the effectiveness (or ineffectiveness) of self-regulation. This is then applied to the UK lease codes based on research carried out by the authors for the UK Government to monitor the success of all three codes. The outcome is a clearer understanding of the possibilities and limitations of using a voluntary solution to achieve policy aims within the property industry.
Resumo:
This paper examines issues related to potential analytical performance systems for global property funds. These will include traditional attribution methods but will also cover the performance concepts of alpha and beta widely used in other asset classes. We look at issues including...what creates beta, and what drives alpha in real estate investment? How can it be measured and isolated? How do these concepts relate to traditional attribution systems? Can performance records and performance fees adequately distinguish between these drivers? In this paper we illustrate these issues by reference to a case study addressing the complete performance record of a single unlisted fund.