Developing a one-dimensional heat and mass transfer algorithm for describing the effect of green roofs on the built environment: Comparison with experimental results

This paper investigates the mathematical modelling of the effect of green roofs on mitigating raised urban temperatures. A dynamic, one-dimensional model is developed, describing heat and mass transfer in building materials, considered as capillary-porous bodies, the vegetated canopy, modelled as a combined plant–air canopy layer, the soil and the air. The model is validated with an experiment, conducted in the Welsh School of Architecture, in Cardiff, in summer 2004. The right choice of parameters that affect the accuracy of the model (such as the expression of the convective heat transfer coefficient and stomatal resistance) is discussed. Special attention is given to the comparison between the experimental results and the outputs of only heat transfer algorithms and heat and mass transfer expressions. Taking these comparisons into consideration, conclusions are drawn about developing an accurate algorithm describing the thermal effect of green roofs on the built microclimate.     

Monte Carlo calculations applied to the parametrical studies in a whole body counter

The use of a Monte Carlo code for the analysis and interpretation of whole body counting measurements is described. The sources of error are analysed and commented to show how a counting geometry can be improved by improving accuracy and precision in a measurement. The effects of body size, contamination distribution and counting geometry are also parameters which can be easily used to improve the quality of a body burden assessment. The optimisation of the detector (position, shielding, shape and size) is also commented on the basis of calculations in the photon energy range usually encountered in routine measurements. The results obtained from these simulations are confirmed by experimental results.     

Laboratory testing of dispersant effectiveness at high pressures

Oil spills remain a serious environmental problem, and can have significant economic and ecological consequences. Despite the advantages, accidental deep-sea oil releases during offshore exploration or production activities are of particular concern as the potential for such incidents increases significantly as we move to deeper waters. Dispersants are important mitigation tools as they have the capability to disperse the oil into a cloud of tiny oil droplets that can be readily degraded by hydrocarbon degraders if suitable environmental conditions prevail. In the case of an offshore incident, the dispersant is injected near the point of crude oil release so that dispersion is more effective. Given that our experience with subsea dispersant use is limited, the effect of pressure on the effectiveness of the dispersant has not been established, and hence, the composition and amount of dispersant to be injected has not been optimized. For typical surface oil spills, dispersant effectiveness is experimentally measured under laboratory conditions by the US-Environmental Protection Agency (EPA) baffled flask test, which was later adapted as ASTM standard method F3251. Despite its extended use, this test cannot be used for testing dispersants at elevated pressures. In order to see whether pressure affects dispersant effectiveness, we developed a simple laboratory test protocol using a high-pressure reactor (HPR). In addition, the effectiveness of five commercially available dispersants (COREXIT™ EC9500A, COREXIT™ EC9500B and COREXIT™ EC9527A, Marichem™, and Oiler 60) applied to a dead light crude oil has been determined at various pressures for the first time, and these values have been related to the standard baffled flask test (BFT) at atmospheric pressure. It is shown that pressure increase adversely affects dispersant effectiveness; however, the effect varies from a few percent to nearly a 50% decrease for a pressure increase of 100 bar depending on the particular dispersant used.     

Staudinger Ligation and Reactions – From Bioorthogonal Labeling to Next-Generation Biopharmaceuticals

In this review, we highlight groundbreaking discoveries and applications of Staudinger reactions in the molecular life sciences, starting from the engineering of the Staudinger ligation as a bioorthogonal reaction until most recent applications in modern bioconjugation methods to generate next-generation biopharmaceuticals. Bioorthogonal reactions refer to a set of chemoselective transformations in biological environments able to take place in presence of naturally occurring functional groups. The Staudinger ligation set a new paradigm of such transformations, resulting in the development of various labeling and bioconjugation strategies for the modification of (bio-)molecules of interest.