Knowledge based quality-driven architecture design and evaluation

Modelling and evaluating quality properties of software is of high importance, especially when our every day life depends on the quality of services produced by systems and devices embedded into our surroundings. This paper contributes to the body of research in quality and model driven software engineering. It does so by introducing; (1) a quality aware software architecting approach and (2) a supporting tool chain. The novel approach with supporting tools enables the systematic development of high quality software by merging benefits of knowledge modelling and management, and model driven architecture design enhanced with domain-specific quality attributes. The whole design flow of software engineering is semi-automatic; specifying quality requirements, transforming quality requirements to architecture design, representing quality properties in architectural models, predicting quality fulfilment from architectural models, and finally, measuring quality aspects from implemented source code. The semi-automatic design flow is exemplified by the ongoing development of a secure middleware for peer-to-peer embedded systems.     

Problems of Salmonella sampling.

Modern husbandry practices, regional concentration of the industry, high stocking densities, uniform age-distribution of birds and continuous feeding promote the spread of poultry diseases. Moreover, the immature state of the intestinal microflora or disturbance of the developing flora by antibiotics increases susceptibility of chicks to salmonellas. If an estimate of the number of salmonella-positive birds in a flock is needed, then the required number of samples can be assessed by using the binomial distribution function. Whenever a qualitative result is sufficient, the samples can be pooled or the flock litter can be sampled using an 'overshoe method', which is a novel, low-cost and rapid technique. An optimal pooling factor can be assessed at low prevalence levels (less than 10%). Serological methods will only detect the presence of antibodies to invasive strains of Salmonella. The sampling interval depends on the strategy of the Salmonella Control Programme. Breeder flocks should be sampled more frequently than meat flocks and laying flocks. The new salmonella standard, ISO 6579-1990, is applicable in the poultry industry. When bacterial numbers are likely to be low, or the organisms in a stressed condition, a pre-enrichment step should be included. In the case of faecal samples, however, pre-enrichment should be omitted. A whole carcass rinsing and massaging method is preferred for the examination of finished carcasses.     

Preventing chlorine deposition on heat transfer surfaces with aluminium-silicon rich biomass residue and additive

Biomass fuels often contain higher concentrations of easily vaporisable alkalis and chlorine than do coal and peat. The more vaporisable the alkalis or chlorine compounds the higher is the risk for ash-related problems. The presence of certain elements may reduce or remove these problems. This work shows how co-combusting of different biomass fuels in a fluidised bed boiler can result in useful interactions that decrease or totally inhibit Cl deposition and bed agglomeration. In a first set of experiments, fuel 1 contained easily vaporised chlorine that produces Cl-rich deposits on superheaters. Fuel 2 was enriched in aluminium silicate, but contained much ash, resulting in low heating value and high load of fly ash. In a second set of experiments, fuel 1 was enriched in Cl and alkalis, which lead to corrosive deposits, bed agglomeration and fouling. As a result of protecting reactions, the mixtures were free from the problems observed during their separate combustion.     

Conference Reviews

Abstract

The desire to teach in a way that acknowledges our position in the world as global citizens faces several challenges, many of which are global in nature. We identify three of these. First, there is the split between “modern” and “traditional” that can be found in a wide range of institutional and historical practices the world over. Second, there is the problem of language which has embedded within it certain historical presumptions. Third, there is the hesitancy in studio teaching to address issues that allow students to see themselves as actors in global history. What we advocate is a global critique of anti-global practices.     

Density functional complexation study of metal ions with poly(carboxylic acid) ligands. Part 1. Poly(acrylic acid) and poly(α-hydroxy acrylic acid)

We have studied metal ion complexation with poly(carboxylic acid) ligands using density functional methods and a continuum-solvation model (COSMO). Geometry optimisations have been carried out for metal complexes of poly(acrylic acid-co-maleic acid), poly(methyl vinyl ether-co-maleic acid), and poly(epoxy succinic acid) oligomers. The complexation energies for Mg²⁺, Ca²⁺, Mn²⁺, and Fe³⁺ have been calculated and they have been corrected with previously determined metal specific correction parameters. The most effective ligand for all the metal ions was found to be poly(epoxy succinic acid). With Ca²⁺, poly(epoxy succinic acid) was found to form 6-coordinated complex with three metal-coordinating carboxylate oxygen, two ether oxygens, and one hydroxyl oxygen atom. All the other metals favoured 5-coordinated complexation geometry with four metal-coordinating carboxyl oxygens and one ether oxygen atom.     

Comparative analysis of available life cycle inventories of cement in the EU

Life cycle inventories (LCIs) are a prerequisite of life-cycle assessments (LCA). This paper conducts a comparative analysis of inventories of several different types of cement produced in Europe. It considers the production of 1 kg of cement from cradle to gate, and all results are based on this mass unit. The reliability of cement inventories is affected by inaccurate or nonrepresentative data, and comparative analysis is difficult due to varying system boundary definitions. Only the four main emissions (CO₂, NOx, SO₂ and dust) are considered. The theoretical model used gives reasonable estimates of emission levels and, thus, can serve as a reference to measured values. In the case of CO₂, this is definitely a feasible alternative to in situ measurements. The emissions derive primarily from the production of clinker, both from the chemical reactions occurring in the kiln and by its fossil fuel consumption.