Approaches to the synthesis of 3-fluoroshikimic acids

Exploitation of the dual dehydrating and fluorodeoxygenating properties of the dialkylaminosulfurtrifluorides has allowed access to the C3-fluorinated analogues of (-)-shikimic acid. (C) 2004 Elsevier Ltd. All rights reserved.

Micellar and surface properties of a poly(methyl methacrylate)-block-poly(N-isopropylacrylamide) copolymer in aqueous solution

Critical micelle concentrations (cmc) of aqueous solutions of poly(methyl methacrylate)-block-poly(N-isopropylacrylamide) were determined at several temperatures by surface tensiometry. Below the lower critical solution temperature (LCST), the low Delta(mic) H-0 determined can be assigned to the PMMA block being tightly coiled in the dispersed molecular state, so that the unfavorable interactions of hydrophobic entities with water are minimized. Above the LCST the cmc value was found to increase; an anomalous behavior that can be directly related to the micelle-globule transition of the hydrophilic block. Interestingly, above the LCST the surface tension of relatively concentrated solutions was found to depend weakly on temperature not following the usual strong decrease with temperature expected for aqueous solutions. (C) 2007 Elsevier Inc. All rights reserved.

Building cluster and shading in urban canyon for hot dry climate - Part 1: Air and surface temperature measurements

Under low latitude conditions, minimization of solar radiation within the urban environment may often be a desirable criterion in urban design. The dominance of the direct component of the global solar irradiance under clear high sun conditions requires that the street solar access must be small. It is well known that the size and proportion of open spaces has a great influence on the urban microclimate This paper is directed towards finding the interaction between urban canyon geometry and incident solar radiation. The effect of building height and street width on the shading of the street surfaces and ground for different orientations have been examined and evaluated. It is aimed to explore the extent to which these parameters affect the temperature in the street. This work is based on air and surface temperature measurements taken in different urban street canyons in EL-Oued City (hot and and climate), Algeria. In general, the results show that there are less air temperature variations compared to the surface temperature which really depends on the street geometry and sky view factor. In other words, there is a big correlation between the street geometry, sky view factor and surface temperatures.

Evidence of systematic approaches to innovation in facilities management

Purpose – This paper seeks to examine the nature of “service innovation” in the facilities management (FM) context. It reviews recent thinking on “service innovation” as distinct from “product innovation”. Applying these contemporary perspectives it describes UK case studies of 11 innovations in different FM organisations. These include both in-house client-based innovations and third-party innovations. Design/methodology/approach – The study described in the paper encompasses 11 different innovations that constitute a mix of process, product and practice innovations. All of the innovations stem from UK-based organisations that were subject to in-depth interviews regarding the identification, screening, commitment of resources and implementation of the selected innovations. Findings – The research suggested that service innovation is highly active in the UK FM sector. However, the process of innovation rarely followed a common formalized path. Generally, the innovations were one-shot commitments at the early stage. None of the innovations studied failed to proceed to full adoption stage. This was either due to the reluctance of participating organisations to volunteer “tested but unsuccessful” innovations or the absence of any trial methods that might have exposed an innovations shortcomings. Research limitations/implications – The selection of innovations was restricted to the UK context. Moreover, the choice of innovations was partly determined by the innovating organisation. This selection process appeared to emphasise “one-shot” high profile technological innovations, typically associated with software. This may have been at the expense of less resource intensive, bottom-up innovations. Practical implications – This paper suggests that there is a role for “research and innovation” teams within larger FM organisations, whether they are client-based or third-party. Central to this philosophy is an approach that is open to the possibility of failure. The innovations studied were risk averse with a firm commitment to proceed at the early stage. Originality/value – This paper introduces new thinking on the subject of “service innovation” to the context of FM. It presents research and development as a planned solution to innovation. This approach will enable service organisations to fully test and exploit service innovations.

A study of students' metacognitive beliefs about foreign language study and their impact on learning

This article reports on an investigation into the language learning beliefs of students of French in England, aged 16 to 18. It focuses on qualitative data from two groups of learners (10 in total). While both groups had broadly similar levels of achievement in French in terns of examination success, they dffered greatly in the self-image they had of themselves as language learners, with one group displaying low levels of self-eficacy beliefs regarding the possibility of future success. The implica tions of such beliefs for students' levels of motivation and persistence are discussed, together with their possible causes. The article concludes by suggesting changes in classroom practice that might help students develop a more positive image of them selves as language learners.

Theoretical and experimental approaches towards the determination of solute effective diffusivities in foods

The aim of this review paper is to present experimental methodologies and the mathematical approaches used to determine effective diffusivities of solutes in food materials. The paper commences by describing the diffusion phenomena related to solute mass transfer in foods and effective diffusivities. It then focuses on the mathematical formulation for the calculation of effective diffusivities considering different diffusion models based on Fick's second law of diffusion. Finally, experimental considerations for effective diffusivity determination are elucidated primarily based on the acquirement of a series of solute content versus time curves appropriate to the equation model chosen. Different factors contributing to the determination of the effective diffusivities such as the structure of food material, temperature, diffusion solvent, agitation, sampling, concentration and different techniques used are considered. (c) 2005 Elsevier Inc. All rights reserved.

Geodetic mass balance of Azarova glacier, Kodar Mountains, eastern Siberia, and its links to observed and projected climatic change

The Kodar Mountains in eastern Siberia accommodate 30 small, cold-based glaciers with a combined surface area of about 19 km2. Very little is known about these glaciers, with the first survey conducted in the late 1950s. In this paper, we use terrestrial photogrammetry to calculate changes in surface area, elevation, volume and geodetic mass balance of the Azarova Glacier between 1979 and 2007 and relate these to meteorological data from nearby Chara weather station (1938-2007). The glacier surface area declined by 20±6.9% and surface lowered on average by 20±1.8 m (mean thinning: 0.71 m a-1) resulting in a strongly negative cumulative and average mass balance of -18±1.6 m w.e. and -640±60 mm w.e.a-1 respectively. The July-August air temperature increased at a rate of 0.036oC a-1 between 1979 and 2007 and the 1980-2007 period was, on average, around 1oC warmer than 1938-1979. The regional climate projections for A2 and B2 CO2 emission scenarios developed using PRECIS regional climate model indicate that summer temperatures will increase in 2071–2100 by 2.6-4.7°C and 4.9-6.2°C respectively in comparison with 1961–1990. The annual total of solid precipitation will increase by 20% under B2 scenario but decline by 3% under A2 scenario. The length of the ablation season will extend from July–August to June-September. The Azarova Glacier exhibits high sensitivity to climatic warming due to its low elevation, exposure to comparatively high summer temperatures, and the absence of a compensating impact of cold season precipitation. Further summer warming and decline of solid precipitation projected under the A2 scenario will force Azarova to retreat further while impacts of an increase in solid precipitation projected under the B2 scenario require further investigation.

Reaction of a phospholipid monolayer with gas-phase ozone at the air-water interface: measurement of surface excess and surface pressure in real time

The reaction between gas-phase ozone and monolayers of the unsaturated lipid 1-palmitoy1-2-oleoyl-sn-glycero-3-phosphocholine, POPC, on aqueous solutions has been studied in real time using neutron reflection and surface pressure measurements. The reaction between ozone and lung surfactant, which contains POPC, leads to decreased pulmonary function, but little is known shout the changes that occur to the interfacial material as a result of oxidation. The results reveal that the initial reaction of ozone with POPC leads to a rapid increase in surface pressure followed by a slow decrease to very low values. The neutron reflection measurements, performed on an isotopologue of POPC with a selectively deuterated palmitoyl strand, reveal that the reaction leads to loss of this strand from the air-water interface. suggesting either solubilization of the product lipid or degradation of the palmitoyl strand by a reactive species. Reactions of H-1-POPC on D2O reveal that the headgroup region of the lipids in aqueous solution is not dramatically perturbed by the reaction of POPC monolayers with ozone supporting degradation of the palmitoyl strand rather than solubilization. The results are consistent with the reaction of ozone with the oleoyl strand of POPC at the air water interface leading to the formation of OH radicals. the highly reactive OH radicals produced can then go on to react with the saturated palmitoyl strands leading to the formation or oxidized lipids with shorter alkyl tails.

Application of the entropy technique and genetic algorithms to construction site layout planning of medium-size projects

Genetic algorithms (GAs) have been introduced into site layout planning as reported in a number of studies. In these studies, the objective functions were defined so as to employ the GAs in searching for the optimal site layout. However, few studies have been carried out to investigate the actual closeness of relationships between site facilities; it is these relationships that ultimately govern the site layout. This study has determined that the underlying factors of site layout planning for medium-size projects include work flow, personnel flow, safety and environment, and personal preferences. By finding the weightings on these factors and the corresponding closeness indices between each facility, a closeness relationship has been deduced. Two contemporary mathematical approaches - fuzzy logic theory and an entropy measure - were adopted in finding these results in order to minimize the uncertainty and vagueness of the collected data and improve the quality of the information. GAs were then applied to searching for the optimal site layout in a medium-size government project using the GeneHunter software. The objective function involved minimizing the total travel distance. An optimal layout was obtained within a short time. This reveals that the application of GA to site layout planning is highly promising and efficient.

A simple relationship between volcanic sulfate aerosol optical depth and surface temperature change simulated in an atmosphere-ocean general circulation model.

In this study we quantify the relationship between the aerosol optical depth increase from a volcanic eruption and the severity of the subsequent surface temperature decrease. This investigation is made by simulating 10 different sizes of eruption in a global circulation model (GCM) by changing stratospheric sulfate aerosol optical depth at each time step. The sizes of the simulated eruptions range from Pinatubo‐sized up to the magnitude of supervolcanic eruptions around 100 times the size of Pinatubo. From these simulations we find that there is a smooth monotonic relationship between the global mean maximum aerosol optical depth anomaly and the global mean temperature anomaly and we derive a simple mathematical expression which fits this relationship well. We also construct similar relationships between global mean aerosol optical depth and the temperature anomaly at every individual model grid box to produce global maps of best‐fit coefficients and fit residuals. These maps are used with caution to find the eruption size at which a local temperature anomaly is clearly distinct from the local natural variability and to approximate the temperature anomalies which the model may simulate following a Tambora‐sized eruption. To our knowledge, this is the first study which quantifies the relationship between aerosol optical depth and resulting temperature anomalies in a simple way, using the wealth of data that is available from GCM simulations.