Energy-Economy Analysis: Linking the Macroeconomic and Systems-Enginering Approaches

A necessary condition for an internally controlled soft-linking of two models is a common, formalised language describing the areas of overlap between the models. This principle is discussed and demonstrated for the softlinking of the macroeconomic and system-engineering models in the scenario work of the Environmentally Compatible Energy Strategies (ECS) Project at IIASA. The Reference Energy System (RES) can describe how the models identify their relevant system in the overlapping areas. Using RES as the common language, a Clearing House is set up to develop the soft-linking procedures and to control the quality of the linking. The procedures permit an interpretation of a key parameter describing energy efficiency improvements in the macroeconomic model into results obtained by the systems-engineering model. Other insights emerge into the "top-down versus bottom-up approaches", which is a label sometimes used to describe the two alternative modelling perspectives. It is illustrative to discuss the insights in term of fallacies that may result from a reliance on one single perspective. We identify here the "reductionist" and the "black box" fallacies

Noninvasive Fluorescence Monitoring of Protoporphyrin IX Production and Clinical Outcomes in Actinic Keratoses Following Short-Contact Application of 5-Aminolevulinate

Topical 5-aminolevulinic acid (ALA) is widely used in photodynamic therapy (PDT) of actinic keratoses (AK), a type of premalignant skin lesion. However, the optimal time between ALA application and exposure to light has not been carefully investigated. Our objective is to study the kinetics of protoporphyrin IX (PpIX) accumulation in AK after short contact ALA and relate this to erythemal responses. Using a noninvasive dosimeter, PpIX fluorescence measurements (5 replicates) were taken at 20-min intervals for 2 h following ALA application, in 63 AK in 20 patients. Data were analyzed for maximal fluorescent signal obtained, kinetic slope, and changes in erythema. Our results show that PpIX accumulation was linear over time, becoming statistically higher than background in 48% of all lesions by 20 min, 92% of lesions by 1 h, and 100% of lesions by 2 h. PpIX accumulation was roughly correlated with changes in lesional erythema post-PDT. We conclude that significant amounts of PpIX are produced in all AK lesions by 2 h. The linear kinetics of accumulation suggest that shorter ALA application times may be efficacious in many patients. Noninvasive fluorescence monitoring of PpIX may be useful to delineate areas of high PpIX accumulation within precancerous areas of the skin

The automorphisms of Petit's algebras

Let σ be an automorphism of a field K with fixed field F. We study the automorphisms of nonassociative unital algebras which are canonical generalizations of the associative quotient algebras K[t; σ]=fK[t; σ] obtained when the twisted polynomialf 2 K[t; σ] is invariant, and were first defined by Petit. We compute all their automorphisms if V commutes with all automorphisms in AutF (K) and n < m-1. In thecase where K=F is a finite Galois field extension, we obtain more detailed information on the structure of the automorphism groups of these nonassociative unital algebras over F. We also briefly investigate when two such algebras are isomorphic

Marginalization of end-use technologies in energy innovation for climate protection

Mitigating climate change requires directed innovation efforts to develop and deploy energy technologies. Innovation activities are directed towards the outcome of climate protection by public institutions, policies and resources that in turn shape market behaviour. We analyse diverse indicators of activity throughout the innovation system to assess these efforts. We find efficient end-use technologies contribute large potential emission reductions and provide higher social returns on investment than energy-supply technologies. Yet public institutions, policies and financial resources pervasively privilege energy-supply technologies. Directed innovation efforts are strikingly misaligned with the needs of an emissions-constrained world. Significantly greater effort is needed to develop the full potential of efficient end-use technologies

Beta-delayed fission and the production of very heavy nuclides from rapid neutron capture processes

The experimental probabilities are larger than expected, indicating an increase in level densities above the fission barriers due to the loss of symmetry at the inner barrier. As a consequence beta delayed fission may occur also in the r-process path. When discussing the production of superheavy nuclides by the r-process, beta delayed fission has therefore to be considered not only in the decay back but also for the cut-off. The results from earlier calculations on the yield of stable nuclides from nuclear explosions and r-process production ratios for chronometric pairs are carried over into a new model with only small changes. (21 refs)