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Abstract Anaerobic digestion of animal by-products was investigated in batch and semi-continuously fed, reactor experiments at 55 °C and for some experiments also at 37 °C. Separate or mixed by-products from pigs were tested. The methane potential measured by batch assays for meat- and bone flour, fat, blood, hair, meat, ribs, raw waste were: 225, 497, 487, 561, 582, 575, 359, 619 dm 3 kg −1 respectively, corresponding to 50–100% of the calculated theoretical methane potential. Dilution of the by-products had a positive effect on the specific methane yield with the highest dilutions giving the best results. High concentrations of long-chain fatty acids and ammonia in the by-products were found to inhibit the biogas process at concentrations higher than 5 g lipids dm −3 and 7 g N dm −3 respectively. Pretreatment (pasteurization: 70 °C, sterilization: 133 °C, and alkali hydrolysis (NaOH) had no effect on achieved methane yields. Mesophilic digestion was more stable than thermophilic digestion, and higher methane yield was noticed at high waste concentrations. The lower yield at thermophilic temperature and high waste concentration was due to ammonia inhibition. Co-digestion of 5% pork by-products mixed with pig manure at 37 °C showed 40% higher methane production compared to digestion of manure alone.

Abstract In this article, we investigate the intergenerational transmission of sustainable consumption practices. Whereas previous studies have used self-reported attitudes and behaviour, this study uses data on actual energy consumption for space-heating and hot water combined with extensive panel data from Danish administrative registers. The paper shows significant intergenerational correlations between the energy consumption patterns of adults and their mothers, also when controlling for the energy consumption of the mother-in-law, where possible. Furthermore, it shows that the intergenerational correlation is slightly stronger for adults with lower income levels. These results suggest that energy consumption practices are shared and reproduced within the family. Following theories of practice, the intergenerational similarities in energy consumption practices refer to bodily learned practices that are indirectly transmitted and negotiated through family relations. In this way, these findings also contribute to a better understanding of how practical understanding regarding how to perform practices is transmitted within more ordinary aspects of consumption that play a less obvious role in distinction. To ensure more sustainable consumption practices in the future, this paper points to the importance of the role of family relations and the transmission of embodied practices.

Cassava pulp is a major by-product produced in a cassava starch factory, containing 50–60% of starch (dry basis). Therefore, in this study we are considering its potential as a raw material substrate for the production of methane. To ensure sufficient amounts of nutrients for the anaerobic digestion process, the potential of co-digestion of cassava pulp (CP) with pig manure (PM) was further examined. The effect of the co-substrate mixture ratio was carried out in a semi-continuously fed stirred tank reactor (CSTR) operated under mesophilic condition (37 °C) and at a constant OLR of 3.5 kg VS m−3 d−1 and a HRT of 15 days. The results showed that co-digestion resulted in higher methane production and reduction of volatile solids (VS) but lower buffering capacity. Compared to the digestion of PM alone, the specific methane yield increased 41% higher when co-digested with CP in concentrations up to 60% of the incoming VS. This was probably due to an increase in available easily degradable carbohydrates as the CP ratio in feedstock increased. The highest methane yield and VS removal of 306 mL g−1 VSadded and 61%, respectively, were achieved with good process stability (VFA:Alkalinity ratio < 0.1) when CP accounted for 60% of the feedstock VS. A further increase of CP of the feedstock led to a decrease in methane yield and solid reductions. This appeared to be caused by an extremely high C:N ratio of the feedstock resulting in a deficiency of ammonium nitrogen for microbial growth and buffering capacity.

Renewable energy has been prioritized in Danish energy policy since the early 1980s. This has led to the current situation where Denmark is one of the leading countries in the world in the field of wind energy utilization. The background for this success is a story about how a society can manage the development and diffusion of sustainable technologies so that they are simultaneously socially acceptable and environmentally benign. Consequently, this article describes the relationship between the organization of wind power and the protection of nature. The aim is to analyse which kinds of public planning and policy can promote wind power and nature protection in a situation where a conflict exists between these two issues. The discussion acknowledges that it has been a serious problem to balance these contrasting considerations. However, it also suggests that the problems seem solvable if technology development, the social organization relating to the use of the technology and proper planning are brought together to work in a spirit of local involvement. © 1998 John Wiley & Sons, Ltd. and ERP Environment

Abstract This work assesses the impacts of aggressive driving behavior on pollutants emissions and energy consumption at a city level. Furthermore, it performs an economic analysis considering the potential avoided emissions and fuel savings and discusses potential policy measures to address this topic. The results showed that aggressive driving significantly impacts energy consumption and emissions, with energy consumption increasing by more than ∼200% and emissions by 330% for aggressive driving compared to non-aggressive driving (in MJ/km and in g/km, respectively). This increment was found to be even higher for diesel vehicles than for gasoline vehicles. On the contrary, gasoline vehicles showed higher percentages of increase for most emissions (CO, NOx and NO). Results also revealed that aggressive driving impacts are higher for local streets when examining the city level. Moreover, the economic analysis showed that significant cost reductions may be achieved by avoiding aggressive driving, reaching up to 52.5 k€ on a daily basis. In conclusion, this study is of particular relevance to policy makers and urban planners, enabling to obtain a comprehensive overview of the impacts of aggressive driving behaviors at a city level and providing new insights to perform further developments and to assess the feasibility of the implementation of policy measures.

Alternative fuels and energy vectors are becoming increasingly important in terms of technical, geopolitical, economic, and environmental aspects. In particular, gaseous fuels and vectors, such as fossil or synthetic natural gas (NG) blended with hydrogen, commonly help provide optimal strategies to reduce global and toxic emissions of internal combustion engines, owing to their adaptability, anti-knock capacity, lower toxicity of pollutants, reduced CO2 emissions, and costeffectiveness. However, diesel engines still represent the reference category among internal combustion engines in terms of maximum thermodynamic efficiency. The possibility offered by dual-fuel (DF) systems to combine the efficiency and performance of diesel engines with the environmental advantages of gaseous fuels has been the subject of extensive investigations. However, the simple replacement of diesel fuel with gaseous fuel does not allow for optimising the engine performance, owing to the high percentage of unburned gaseous fuel, which compromises the potential reduction of CO2; therefore, more complex combustion strategies should be realised. In this study, with the aim of improving the DF combustion process, an experimental investigation was performed to analyse low-temperature combustion (LTC), using NG and two enriched hydrogen-compressed NG blends as primary fuels. The LTC mode was activated by means of a very early advanced pilot injection and carried out in two close steps. The double pilot injection was used to control the energy release rate in the first combustion stage, thereby minimizing the increase of the rate of pressure and allowing the extension of the operation range under LTC. The experimental activity was also focused on analysing the particle emissions, as it is well known that these emissions, together with those of nitrogen oxide, constitute the main pollutants resulting from diesel fuel combustion. The results demonstrated the potential to reduce the unburned fuel, NOx, and particle emissions simultaneously, while maintaining equivalent CO2 emissions to a diesel-only engine. Both the timing and pressure of the pilot injection proved to be critical parameters for optimising the emissions and performance

Stories play an exceptionally important role in how people assign value to a place. Taken together, all those stories essentially give a place an identity. The aim of placemaking is to ensure that the people using a place can appreciate that place. Placemaking approaches are focussed on strategic interventions in a place and aimed at changing the meaning and value of that place for local people, thus creating a qualitative place for enhanced storytelling. Using greenery is a common approach in place-making. Urban greenery has gone through a process of emancipation in the past 15 years. This emancipation has led to awareness that urban greenery is about more than just ecology and biodiversity, but also has social and economic consequences for a city’s fortunes. It is clear that green spaces do not stand alone: they are part of a complex urban system, and the use of green spaces in this complex system has immediate repercussions for how the city functions. With the changing role of green spaces within cities, the need to manage these spaces is emphasized. In this sense, the place-making approach, along with the storytelling approach could provide valuable insight on the planning and management of green spaces within the urban environment, with the aim to enhance quality of life by means of the social connection between people, the users of the space, and the qualitative place provided. This research illustrated that green space managers would need more social and organizational skills to manage modern urban green spaces in an attempt to create qualitative, usable spaces for citizens, spaces that are built upon stories and spaces that would further enable future stories of citizen life. The Story Behind the Place: Creating Urban Spaces That Enhance Quality of Life (PDF Download Available). Available from: https://www.researchgate.net/publication/271918395_The_Story_Behind_the_Place_Creating_Urban_Spaces_That_Enhance_Quality_of_Life [accessed Dec 21, 2015].

In themediumtolongterm,lowfossilfuelavailabilitywillmakeitnecessarytofindalternatives.Mass productionofbiofuelswillnotbeapracticalsolutionbecauseitrequiresstrongcompetitionforland that isusedforgrowingfood.Therefore,itwillbenecessarytorevisetheframeoftransportation energy sources.Thenumberofpurelight-andheavy-dutyelectricvehiclescouldincreaseinurban areas.Instead,itwillbehardtofindaviablealternativetotheinternalcombustionengineforextra- urban transportvehicles,thereforealternativesyntheticfuelscouldbeusedtocompensateforfossil fuel depletion.Asidefromasmallshareobtainablefrombiomass,mostsyntheticfuelsareexpectedto be obtainedfromcoal.Amongthese,syntheticnaturalgasrepresentsaverygoodsolution.Infact, syntheticnaturalgaswillbeadvantageouswithrespecttohydrogen,whoseon-boardstoragewillbean unsolvedprobleminthemediumterm,andwithrespecttosyntheticliquidfuels,whichrequiremore energy intheproductionphase.Moreover,thecarboncontentofliquidfuels,whichishigherthanthat of gaseousfuels,willberesponsibleforhigherCO2 emissionsfromvehicles.Currently,naturalgashas poor diffusioninthetransportsector,andthispaperhighlightsthemotivationsforfavouringapolicy aimedatincreasingtheshareofgaseousfuel-poweredvehicles.Inadditiontothelowenvironmental impact,syntheticnaturalgasalsooffersthepossibilityofoptimisingtheutilisationoffutureresources