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Natural ventilation performance is one of the key climate control parameters for Canary type greenhouses, which are rapidly expanding along the Atlantic coast in Morocco. The use of insect screens significantly reduces airflow and increases thermal gradients inside the greenhouse. The aim of this study was to analyze the natural ventilation performances in real cultural conditions of a large-scale Canary type tomato greenhouse (1.1 ha) equipped with insect screens on the vent openings. A global energy balance of the greenhouse was used, allowing for the determination of air exchange rates. The greenhouse ventilation performance was compared with those of other greenhouses types and discussed with respect to the improvement of greenhouse vent design, insect screen types, and ridge and crop row orientation. The results confirm the strong dependence of greenhouse ventilation rate on wind speed and ventilation opening location. In addition, results show a significant reduction of the ventilation rate compared with other greenhouse types: the insect screen reduced the greenhouse ventilation rate by 46%, and the tomato rows that were oriented perpendicular to the prevailing air movement through the greenhouse reduced the ventilation rate by 50%. From this analysis, practical improvements are proposed and discussed in the context of protected crop production in the coastal area of Morocco.

Abstract Red deer bone collagen from Rochedane in the Jura (France) was analysed for carbon and nitrogen isotopic composition. The specimens range in 14C age from about 13 000 to 8000 yr BP (uncalibrated), and cover the Late-Glacial and Early Holocene, a time period during which climatic conditions shifted from periglacial to temperate. The carbon isotopic compositions of red deer collagen suggest changes in the vegetation cover around the site that are consistent with other palaeoenvironmental indicators, such as the palynological record in the Jura. The nitrogen isotopic compositions exhibit a large range of around 6‰ interpreted as reflecting changes in the intensity of N cycling coeval to vegetation changes. Red deer bone collagen appears thus as a valuable proxy for reconstructing palaeoenvironmental changes in continental western Europe during the Late-Glacial and Holocene.

Biological invasions in wetlands by Water Primroses (Ludwigia grandiflora ssp. hexapetala and L. peploides ssp. montevidensis) are an increasing problem especially in wet meadows. The aim of this paper is to quantify differences between species and the adaptation of these amphibious plants in order to establish the consequences for site managers. The hypotheses were: (i) that these species differ in biomass and morphology, and (ii) that terrestrial habitats determine particular adaptations such as reduced biomass, more roots and a bushy form. Biomasses from five sites were collected, following seasonal changes and biological traits were measured on selected plants. Comparing species in aquatic habitats, L. peploides produced less biomass than L. grandiflora. Comparing habitats for L. grandiflora, the biomass in meadows was almost twice that in dykes, particularly due to old stems, the converse of the hypothesis. Terrestrial forms were characterized by a bushy morphology, with shorter internodes and stems, as well as more secondary ramifications, while in aquatic habitats the plant architecture was simpler. Models were built linking morphology to species, sites and water conditions. Adaptations to terrestrial habitats of a particularly resistant form with a significant potential biomass are practical constraints for farmers and managers.

Abstract In this paper, we investigate the construction of markets for clean technologies by examining the mechanisms through which new technologies succeed (or fail) to be transformed into goods that are both environmentally and economically valuable. We envisage this process as a particular form of market innovation in which new product qualities are inscribed into market architectures. We focus on the market for clean technologies that emerged as a result of the EU Integrated Pollution Prevention and Control (IPPC) directive that required polluting industries, including livestock farms, to implement the “best available techniques” in order to reduce their emissions. Our case study traces a Danish start-up firm's endeavors to commercialize one such “best available technique:” a solution for reducing ammonia emissions from farms. Building on the literature on the shaping of markets, we show that the construction of a market for clean technologies hinges upon the composition of a complex network of actors with divergent, and sometimes conflicting, interests, in which market devices (in this case, a technology list) play a pivotal role. More generally, the paper contributes to discussions on controversies and performativity in market practices and on the construction of markets designed to address environmental issues.

Sustainability assessment is a critical issue for the biodiesel production chain. The constant growth of the biodiesel industry has generated important sustainability concerns, such as competition with food production, indirect land use change, and impacts on water, biodiversity and social values. Government policies consider that quantitative, robust and independent sustainability assessment is vital to estimate the extent to which the biodiesel industry impacts sustainability issues. However, weaknesses in the definition of adequate indicators to measure the sustainability of biodiesel production have been identified. In this context, this work proposes a hierarchical assessment framework based on sustainability dimensions, principles, criteria and indicators. To do this, after a systematic literature review, a first version of the framework was proposed. Then, to define the final framework, a validation strategy based on expert survey consultations and a descriptive statistical analysis were developed. In order to define the principles and criteria importance for sustainability assessment of biodiesel, 62 experts answered an online survey assessing three attributes: relevance, ease of measurement and reliability. The first result of the validation analysis was the definition of a framework composed of five dimensions (social, economic, environmental, political and technological), 13 principles, and 30 criteria that would be part of a sustainability assessment of biodiesel production. The second result was the identification of potential groups and relationships between principles and criteria represented through data visualization techniques. The validated framework provides the basis for defining future studies about interdimensional principles and criteria. Also, the proposed sustainability assessment framework could be adapted and applied to biodiesel production in specific contexts.

Urban water networks can contribute to the energy transition of cities by serving as alternatives sources for heating and cooling. Indeed, the thermal energy potential of the urban water cycle is considerable. Paris is taken as an example to present an assessment of the field performance of a district-scale waste water heat recovery system and to explore potential techniques for emergency cold recovery from drinking or non-potable water networks in response to heat-waves. The case heat recovery system was found to provide significant greenhouse gas emission reductions (up to 75%) and limited primary energy savings (around 30%). These limited savings are found to be mainly due to the performance of the heat pump system. Three emergency cold recovery techniques are presented as a response to heat-waves: subway station cooling, ice production for individual cooling, and "heat-wave shelter" cooling in association with pavement-watering. The cold generation potential of each approach is assessed with a special consideration for mains water temperature sanitary limitations. Finally, technical obstacles and perspectives are discussed.

Second generational biofuels offer the possibility of using biomass residues such as agricultural or industrial wastes for use in internal combustion engines. However, biochemical and thermochemical conversions to liquid or gaseous fuels require elaborate and expensive pre-treatment facilities. Decreasing the complexity, size and cost of these facilities can alleviate sourcing constraints, increasing implementation in a wide range of applications. Remaining in its original solid form, biomass powder is a simplified biofuel requiring only drying and milling which is technically and economically feasible at a wide range of scale. By exploiting its explosive character, we can operate a standard diesel engine directly on powder for energy generation. The demand for a low-tech biofuel along with advances in milling techniques motivates the idea of using biomass powder in an engine. In this paper we provide experimental proof by operating a diesel engine on fumigated Wheat Straw and Pine Bark dust each for 35 minutes. Emissions, operational performance and combustion data show that biomass powders from agricultural residues should be considered for use as an adaptable technology for existing engine installations. Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 618-621