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Abstract. The impact of multiphase reactions involving nitrogen dioxide (NO2) and aromatic compounds was simulated in this study. A mechanism (CAPRAM 2.4, MODAC Mechanism) was applied for the aqueous phase reactions, whereas RACM was applied for the gas phase chemistry. Liquid droplets were considered as monodispersed with a mean radius of 0.1 µm and a liquid content (LC) of 50 µg m-3. The multiphase mechanism has been further extended to the chemistry of aromatics, i.e. reactions involving benzene, toluene, xylene, phenol and cresol have been added. In addition, reaction of NO2 with dissociated hydroxyl substituted aromatic compounds has also been implemented. These reactions proceed through charge exchange leading to nitrite ions and therefore to nitrous acid formation. The strength of this source was explored under urban polluted conditions. It was shown that it may increase gas phase HONO levels under some conditions and that the extent of this effect is strongly pH dependent. Especially under moderate acidic conditions (i.e. pH above 4) this source may represent more than 75% of the total HONO/NO2 - production rate, but this contribution drops down close to zero in acidic droplets (as those often encountered in urban environments).

AbstractHydrodynamics plays a major role in wet grinding processes used to produce nanoparticles, but its influence on the mechanisms of fragmentation is not fully understood. The focus is on hydrodynamics in the gap between two grinding beads. Using particle image velocimetry in a large‐scale experiment, the velocity field between the beads has been investigated when the beads get closer (down to one‐tenth of their radius). Different configurations have been studied, varying from frontal approach to tangential collision. Finally, a capture probability of suspended particles has been estimated.

A promising technology for renewable energy is energy piles used to heat and cool buildings. In this research, the effects of bio-cementation via microbially induced calcite precipitation (MICP) using mixed calcium and magnesium sources and the addition of fibres on the thermal conductivity of soil were investigated. Firstly, silica sand specimens were treated with cementation solutions containing different ratios of calcium chloride and magnesium chloride to achieve maximum thermal conductivity improvement. Three treatment cycles were provided, and the corresponding thermal conductivity was measured after each cycle. It was found that using 100% calcium chloride resulted in the highest thermal conductivity. This cementation solution was then used to treat bio-cemented soil samples containing fibres, including polyethylene, steel and glass fibres. The fibre contents used included 0.5%, 1.0% and 1.5% of the dry sand mass. The results show that the glass fibre samples yielded the highest thermal conductivity after three treatment cycles, and SEM imaging was used to support the findings. This research suggests that using MICP as a soil improvement technique can also improve the thermal conductivity of soil surrounding energy piles, which has high potential to effectively improve the efficiency of energy piles.

AbstractThe concept of a ‘just transition’ to a low‐carbon economy is firmly embedded in mainstream global discourses about mitigating climate change. Drawing on Karl Polanyi's political economy elaborated inThe Great Transformation, we interrogate the idea of a just transition and place it within its historical context. We address a major contradiction at the core of global energy transition debates: the rapid shift to low‐carbon energy‐systems will require increased extraction of minerals and metals. In doing so, we argue that extractive industries are energy and carbon‐intensive, and will enlarge and intensify social and ecological injustice. Our findings reveal the importance of understanding how the idea of a just transition is used, and by who, and the type of justice that underpins this concept. We demonstrate the need to ground just transition policies and programmes in a notion of justice as fairness.

The net energy (NE) system takes into account the metabolic utilisation of energy and has been proposed as a superior system for characterising the energy value of feeds. In growing pigs, the inefficiency of ME utilisation for NE (or the heat increment, HI) is dependent on many factors, among them the genotype, which implies that published NE prediction equations may not apply across all genotypes. We conducted a study to investigate the effect of two genotypes (Yorkshire-Hampshire♀ × Duroc♂; YH × D) and Large white♀ × Landrace♂; LW × LR) on heat production (HP) and NE value of a corn soybean meal-based diet fed to growing pigs. The diet met or exceeded the nutrient specifications of 20-50 kg b.w. pigs according to NRC (1998). A total of sixteen barrows were used, eight of each genotype (initial b.w. of 20.1 ± 1.1 and 19.0 ± 0.9 kg for YH ×D and LW × LR, respectively). Pigs were initially fed at 550 kcal/kg b.w.-0.60/day (high ME intake) for determination of DE and ME in metabolism crates. Thereafter, HP was measured using an indirect calorimeter at either high ME or 330 kcal/kg b.w.-0.60/day (low ME intake) to estimate fasting HP (FHP) by regression. Pigs were allowed a 3-d adaptation period at low ME intake before measurement of HP. Irrespective of the genotype, a reduction of ME intake resulted in a decrease (P < 0.0001) of HP (352 for high ME vs. 292 kcal/kg b.w.-0.60/day for low ME). Pigs of LW × LR tended (P = 0.07) to have higher HP than those of YH× D and their estimated FHP was 175 and 103 kcal/kg b.w.-0.60/day, respectively. The determined diet NE value was lower for the YHxD genotype (2,307 vs. 2633 kcal/kg DMI, P = 0.01) than for the LW × LR genotype. Pigs of LW × LR genotype showed lower (179 vs. 226 kcal/kg b.w.-0.60/day, P = 0.003) HI than YH × D genotype and were determined to retain less energy as protein (100 vs. 123 kcal/kg b.w.-0.60/day, P =0.04) and more energy as fat (73 vs. 42 kcal/kg b.w.-0.60/day, P = 0.04). The diet NE value was 96% (LW × LR) and 81% (YH × D) of the predicted NE from published equations. In conclusion, a corn-soybean meal fed at equal amounts resulted in different HP and NE value depending on genotype.

Even with the benefits of sustainability and climate change reporting, there is limited information on how municipalities are reporting on performance for external stakeholders in comparison with private sector organizations. The purpose of this research was to gain an understanding of the current state of sustainability and climate change reporting at the local level and to investigate the extent to which municipalities across Ontario, Canada, report. We used content analysis to identify the presence or non-presence of information on the websites of 38 municipalities and analyzed the results using descriptive statistics. Our analysis showed that the sample municipalities were not widely reporting on sustainability or climate change performance. Also, we identified a gap between the number of plans and reports produced by sample municipalities, with the latter being less common, indicating a need for an improved evaluation of plan implementation. Further, we found that a provincial regulation that required municipalities to make their energy conservation and demand management plans public did not guarantee publication of the plan on a municipality’s website. This study contributes to the growing field of sustainability and climate change planning and reporting by local governments and offers empirical evidence specific to Ontario, Canada.