Aspects of Compositionality

We introduce several senses of the principle ofcompositionality. We illustrate the difference between them with thehelp of some recent results obtained by Cameron and Hodges oncompositional semantics for languages of imperfect information.     

Increasing trends of total organic carbon concentrations in small forest lakes in Finland from 1987 to 2003

Trends in total organic carbon (TOC) concentrations over the period 1987-2003 were studied in 13 small forest lakes. Recovery from acidification (reduced SO(4) deposition) and long-term changes in runoff as potential drivers for the trends were examined. The results showed that TOC concentrations have increased throughout Finland. Ten of the 13 lakes showed a significant increasing TOC trend (p<0.05), and included both clear water and humic lakes. The largest annual increase in TOC occurred in lakes with the largest average concentrations. The magnitude of the TOC trends were not significantly related to the proportion of peat soils in the catchment but the catchment size was an important predictor. Decreasing SO(4) deposition and improved acid-base status in soil due to the recovery from acidification implied an increased mobilisation of organic acids and TOC. There was little evidence that the long-term increasing trend in TOC concentrations was related to long-term changes in runoff. However, large seasonal and inter-annual fluctuations in runoff did appear to affect TOC concentrations for a number of years.     

Model of fragmentation of limestone particles during thermal shock and calcination in fluidised beds

Fragmentation of limestone due to thermal shock and calcination in a fluidised bed was studied through experiments and modelling. The time for heating was estimated by model calculations and the time for calcination by measurements. Fragmentation due to thermal shock was carried out by experiments in a CO₂ atmosphere in order to prevent the effect of calcination. It was found to be much less than fragmentation due to calcination. Average particle sizes before and after fragmentation are presented for several types of limestone. The effects of particle size and gas composition on the primary fragmentation were studied through experiments. Increasing the fluidisation velocity increased the tendency to fragment. The evolution of the particle size distribution (PSD) of limestone particles due to thermal shock and during calcination (or simultaneous calcination and sulphation) were calculated using a population balance model. Fragmentation due to thermal shock is treated as an instantaneous process. The fragmentation frequency during calcination is presented as exponentially decaying over time. In addition to the final PSD, this model also predicts the PSD during the calcination process. The fragmentation was practically found to end after 10 min. Furthermore, a population balance method to calculate the particle size distribution and amount of limestone in fluidised beds in dynamic and steady state, when feeding history is known, is presented.     

Bioleaching and recovery of metals from final slag waste of the copper smelting industry

Solid waste from the copper smelting industry may be harmful if disposed of in the environment, but it may be a valuable resource if metals can be recovered. The purpose of this study was to evaluate the acid bioleaching of metals from a sample of final smelter slag and the recovery of metals from the leach liquors. Bioleaching was tested in a continuously stirred tank reactor (CSTR) at 20-25 °C with 5% pulp density (particle size 75% <47 μm). The yields of metal solubilization after 29 days of contact were 41% Fe, 62% Cu, 35% Zn and 44% Ni. Metals were precipitated in a separate CSTR by titrating the leach liquors with sulfide-rich effluent from a sulfate-reducing fluidized-bed reactor (FBR) (25 °C) to desired pH values. Over 98% of the Cu precipitated at pH ? 2.8 and over 99% of the Zn precipitated at pH ? 3.9. The precipitation of Ni and Fe required higher pH values and was less efficient than Cu and Zn recovery. In addition, bulk precipitation of metals was also tested by feeding the leach liquor directly to another sulfate-reducing FBR. In order to reduce its toxicity and maintain stable sulfate reduction performance in the FBR, the leach liquor had to be diluted ten-fold and the pH adjusted from 0.6 to approximately 4.     

Bioelectricity production on xylose with a compost enrichment culture

An exoelectrogenic culture was enriched on 1.0 g/L xylose from a compost sample in two-chamber microbial fuel cells (MFCs). Electricity production was optimized by changing mixing type, external resistance, xylose concentration and pH. Furthermore, the changes in microbial communities after each optimization step were monitored with PCR-DGGE. Electricity production was highly dependent on operational conditions that affected power densities (PD), Coulombic efficiencies (CE), substrate degradation, utilization of soluble metabolites for electricity production and stability of MFC performance. The optimum operational conditions for electricity production were without mixing, 100 Ω external resistance, 0.5 g/L xylose and pH 7. With optimized operational conditions PD of 590 mW/m² and CE of 82% were obtained. Microbial community composition, consisting mainly of Geobacter sulfurreducens, Escherichia coli, Sphaerochaeta sp. TQ1 and Bacteroides species, was mainly affected by MFC configuration, i.e. electrical connections, which likely affected the anode potential.     

Diversifying meat consumption patterns: consumers' self-reported past behaviour and intentions for change

This study analysed meat consumption patterns among Finnish consumers, considering both stated past changes and intended future changes. Consumer segments with different patterns of and reasons for change were identified. Latent class analysis revealed six consumer clusters that formed three major cluster blocks. The first block, comprising 48% of the consumers, had established consumption patterns and no intentions to change them. In the second block, with 13% of the consumers, consumption patterns had already shifted towards more vegetables and less meat. The third block, with 39% of the consumers, was identified to be in the middle of a change with a general tendency to reduce the use of meat and increase the use of vegetables. Although the environmental effects of meat and animal welfare issues were important reasons for change in some clusters, healthiness was the most salient stated reason for changing consumption habits.     

Natural organic matter (NOM) removal and structural changes in the bacterial community during artificial groundwater recharge with humic lake water

This study evaluated the removal of natural organic matter (NOM) and structural changes in the microbial community during infiltration of humic lake water at three artificial groundwater recharge (AGR) sites in Finland. The three sites were at waterworks in H?meenlinna, Jyv?skyl? and Tuusula, sites A, B and C, respectively. Site A used groundwater recharge by both basin and sprinkling infiltration, site B used only sprinkling infiltration, and site C used only basin infiltration. Reductions of total organic carbon at sites A, B and C were 91%, 84% and 74%, respectively, in the winter, and 88%, 77% and 73%, respectively, in the summer. The Finnish national recommended value of 2 mg/l for TOC was achieved at all sites and the TOC of natural groundwater at site C was much lower, at 0.6 mg/l. Large molecular fractions of NOM were removed more efficiently than the smaller ones. Total amount of DAPI-stained cells decreased during infiltration at sites A, B and C in winter by 94%, 94% and 75% and in summer by 96%, 97% and 94%, respectively. Bacterial communities in raw waters and extracted groundwaters were diverse with changes occurring during infiltration, which was shown by DNA extraction followed by PCR of 16S rRNA genes and denaturing gradient gel electrophoresis (DGGE) fingerprinting. While the natural groundwater microbial community was diverse, it was different from that of the extracted groundwater in the AGR area. Simultaneous organic carbon removal and the decrease of bacterial counts during infiltration indicated biodegradation. In addition, the changing DGGE profiles during the process of infiltration, demonstrated that changing environmental conditions were reflected by changes in bacterial community composition.     

High-accuracy wave field reconstruction: decoupled inverse imaging with sparse modeling of phase and amplitude

We apply a nonlocal adaptive spectral transform for sparse modeling of phase and amplitude of a coherent wave field. The reconstruction of this wave field from complex-valued Gaussian noisy observations is considered. The problem is formulated as a multiobjective constrained optimization. The developed iterative algorithm decouples the inversion of the forward propagation operator and the filtering of phase and amplitude of the wave field. It is demonstrated by simulations that the performance of the algorithm, both visually and numerically, is the current state of the art.