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A qualitative research approach was chosen to analyse the conceptions of pupils attending elementary school from Canada (N = 135), France (N = 30) and Morocco (N = 92) between 10 and 12 years of age. Their conceptions were identified while being mobilised on energy transformations during the working of a simple electric circuit made of a battery, a bulb and electric wires: light, thermal, electrical and chemical. With paper and pencil, they completed a questionnaire made up of six questions during a forty-five minute period. The analysis of the data of the experimentation demonstrates that the majority of the conceptions identified are naïve compared to those constructed by the scientists. It also shows that their conceptions are similar in spite of the different cultures. The results confirm the findings of the international community of researchers in didactics of sciences regarding the universality of children's conceptions about the working of simple electrical circuits. These findings have implications on teacher training, science teaching and learning in a multiple cultural environment.

In this paper we describe the results of some experiments about using surprising physics demonstrations, presented as magical phenomena followed by scientific explanations, for introducing physics topics in several teaching contexts. All the demonstrations have been designed to be implemented with easy to get and cheap materials, so that students can reproduce them at home. This approach has been exploited in Italian high schools, Italian elderly people education and French primary schools, with good results.

The question of how to teach energy has been renewed by recent studies focusing on the learning and teaching progressions for this concept. In this context, one question has been, for the most part, overlooked: how should energy be defined throughout schooling? This paper addresses this question in three steps. We first identify and discuss two main approaches in physics concerning the definition of energy, one claiming there is no satisfactory definition and taking conservation as a fundamental property, and the other based on Rankine's definition of energy as the capacity of a system to produce changes. We then present a study concerning how energy is actually defined throughout schooling in the case of France by analyzing national programs, physics textbooks, and the answers of teachers to a questionnaire. This study brings to light a consistency problem in the way energy is defined across school years: in primary school, an adapted version of Rankine's definition is introduced and conservation is ignored; in high school, conservation is introduced and Rankine's definition is ignored. Finally, we address this consistency problem by discussing possible teaching progressions. We argue in favor of the use of Rankine's definition throughout schooling: at primary school, it is a possible substitute to students' erroneous conceptions; at secondary school, it might help students become aware of the unifying role of energy and thereby overcome the compartmentalization problem.

This paper presents an analysis of the impact of the indoor classroom environment on students' learning efficiency. The research is based on a classroom smart monitoring and a questionnaire about the students' assessment of the comfort conditions and learning efficiency. Multisensor devices are used to measure the indoor temperature, relative humidity, and CO2 concentration at the students' desks. Data analysis concerned an investigation of the spatial and temporal variation of the comfort parameters and their correlation with students' assessment of comfort conditions and learning efficiency. The results show a significant spatial variation in the indoor comfort conditions, particularly for temperature and CO2 concentration. The indoor temperature could exceed by up to 5 °C, the temperature threshold limits value in France's public buildings. At the beginning of the class, the learning efficiency correlates well with the students' assessment of comfort conditions. At the end of the class, the results show a weak correlation with both recorded comfort parameters and the students' assessment of the indoor conditions. The results indicate a decrease in learning efficiency during the class. However, students do not mainly attribute this decrease to the degradation in indoor conditions. [ABSTRACT FROM AUTHOR]

This paper proposes an integrated model for multi-machines dynamic lot sizing aiming to produce a single item, considering the energy consumption during the production horizon. The objective is to find, firstly, the optimal lot size as well as the number of machines that satisfy a random demand under given service level and secondly, maintenance plan depended to production planning to minimise the total production, energy and maintenance costs. In fact, the problem of energy consumption is one of the most evoked topics especially with the decision of many governments to reduce theirs (For example France is willing to reduce the total consumption by 20% by 2020). The keys of this study are to consider, firstly, the correlation between the forecasting of demand, the variation of the working machines as well as their production rates under energy constraint and secondly the correlation between the production cadences and the maintenance strategy of all machines. [ABSTRACT FROM AUTHOR]

Energy consumption in the social housing sector constitutes a major economic, social, and environmental issue, because in some countries such as France, social housing accounts for about 19% of the housing sector. In addition, this sector suffers from ageing, which results in high energy consumption, deterioration in the occupant quality of life, and high pressure on the budget of low-income occupants. The reduction of the energy consumption in this sector becomes a "must". This reduction can be achieved through energy renovation and innovation in both energy management and occupant involvement by using smart technology. This paper presents a contribution to this goal through the investigation of the impact of smart monitoring on energy savings. The research is based on monitoring of comfort conditions in an occupied social housing residence in the North of France and the use of building thermal numerical modeling. Results of monitoring show that the indoor temperature largely exceeds the regulations requirements and the use of a smart system together with occupant involvement could lead to significant savings in heating energy consumption. The novelty in this paper concerns the use of comfort data from occupied social housing residence, occupation conditions, and building thermal modeling to estimate energy savings. The proposed methodology could be easily implemented to estimate heating energy savings in social housing buildings that lack individual energy consumption monitoring. [ABSTRACT FROM AUTHOR]

The governments of Britain, France, and the United States are seeking to promote renewed investment in nuclear power through metagovernance. Metagovernance describes the way governments can leverage state power and resources to shape the behavior of networked actors to advance policy goals. To metagovern, governments use a variety of policy tools but the factors shaping the design of these policy tools remains unclear. Grid-group cultural theory is used to show that the design of the policy tools used in metagovernance reflects both an underlying cultural bias within government and prevailing institutional circumstances. The paper demonstrates the utility of cultural theory in the study of metagovernance. [ABSTRACT FROM AUTHOR]

The relevance, relative importance and colinearity of input parameters to the results of building energy demand forecasts were investigated. Two calendar years of historical data including weather variables and days of the week were used. The study also aimed to assess the performance of multiple-linear-regression, support-vector-machine and artificial-neural-network models for predicting the daily heating, ventilation and air-conditioning energy consumption of a commercial building in France. Mean absolute error, root-mean-square error and coefficient of variation of root-mean-square error were selected as the performance criteria. The results showed that the best performance was achieved through the artificial-neural-network model according to all performance measures. Besides, the other two models were not able to meet the prediction requirements for energy consumption in a building since their coefficient-of-variation-of-root-mean-square-error values were not below 30%. The results also indicated that there was multiple colinearity between the number of degree days and outdoor temperature. Furthermore, the most significant parameter for daily energy consumption was found to be the number of degree days, followed by global radiation, sunshine rate and the day of the week. [ABSTRACT FROM AUTHOR]

Buildings are the largest contributors to households' energy footprints. If both the energy for household mobility and the embodied energy are added to the energy for heating/cooling, domestic hot water, lighting, buildings are by far the main problem of energy consumption in France. This paper presents a review of the evolution of the main drivers of CO 2 emissions by buildings in France. Eventually, the paradox of the effect of density is discussed. Lower density of cities increases the energy spent per inhabitant, in particular for transport, but may also increase the production of low-carbon renewable energies, shifting the global energy balance and influencing the prospective studies of future, energy efficient, smart cities. [ABSTRACT FROM AUTHOR]

The energy of water masses is a first-order factor that controls the essential physicochemical dynamics of a water body. Its study allows one to understand the roots of the processes that occur at the water-mass, water-atmosphere and water-sediment interfaces. The analysis of the Thomas Pond in the Brenne region gives a valuable overview of energy stock evolution on a yearly scale. It highlights the direct impact of this evolution on thermal stratification and the potential for evaporation and exchange with the atmosphere. The study of evaporation remains challenging due to the complexity of the energy processes and factors involved. Its estimation using formulas, which are mostly empirical, is one of the most used means for studying the process. The studied pond shows a natural stratification during the summer season, however often fragile and disturbed by other climatic factors such as wind and precipitation. This disruption leads to increased exchanges between the pond and the atmosphere. The methods used to estimate pond-atmosphere exchanges, namely evaporation, vary in values ranging between 1 mm/d to > 15 mm/d. Among these methods, three stand out and seem to give reasonable values. This observation is based on the noticeable drop of the pond's water level during the period of non-communication with the outside, which corresponds to 65 mm. The energy required for this evaporation varies between 600 W/m2 and 1500 W/m2, except for the Smith model, that slightly overestimates this parameter. The regulation of ponds' water volumes by managers, the increased duration of bungs closure and the intermittence of precipitations in recent years exacerbate the reduction of direct inputs to ponds and the aggravates the impacts of a changing climate. Under the effect of increasing air temperatures, losses by evaporation will also increase significantly. If we generalise the results obtained to all of the Brenne Park water bodies (4500 ponds of the park), losses by evaporation will lead to a significant water deficit of the Loire basin. From this study, the use of deep learning ensemble models was found to provide better short-term predictions (RMSE between 0.003 and 0.006 for all methods), thus confirming the effectiveness of these methods for similar applications. [ABSTRACT FROM AUTHOR]

A novel approach to the intensity of archaeological fires is proposed, based on a combination of archaeological observations and analyses of sedimentary hearths with relevant proxies obtained from using experimental combustion structures. In this work, two different structures were built and monitored. They aimed at reproducing two types of archaeological hearth morphology encountered at the Bronze Age site of the cave of Les Fraux (Saint Martin de Fressengeas, Dordogne, France). A series of fires was constructed and a large amount of data was collected: temperature curves, wood consumption and observations on substratum evolution. A numerical code for heat transfer was developed to model heat propagation from the surface to the underlying sedimentary layers, the input parameters of which were adapted to fit the thermal evolution observed with the experimental fires. We found that two archaeological parameters are fundamental to characterise the intensity of the fire: the paleotemperature reached at the surface of the burnt sediment (which in our case was determined by thermoluminescence analyses) and the depth of the rubefaction front as an indicator of a 250 °C isothermal surface. We then estimated the duration of an equivalent single fire that would correspond to one of the archaeological hearths investigated. Finally, with the wood consumption recorded during the fire experiments, and the estimated firing duration, the energy involved was evaluated. When generalised to the study of archaeological hearths, this approach could be of great interest in firing intensity evaluation (temperature/time/energy). [ABSTRACT FROM AUTHOR]

The ecological consequences of seed size variation have been studied extensively in plants. Curiously, little attention has been paid to the qualitative and quantitative variation of the seed-stored molecules and on their ecological significance. Here, we analysed the oil content and oil composition of ca. 200 weed seed species from agricultural fields in France based on single seed accessions, concentrating on interspecies differences and ignoring within-species variation. The relationships between seed weight, oil %, fatty acids ( FAs) and the energetic value of the seed and its antioxidant properties were also investigated. The antioxidant activity could contribute to protect the oily seed reserves from alteration over time. Among the species analysed, we found a considerable quantitative (oil%) and qualitative variation of FAs stored in the seeds. Such variation was largely related to the plant family of the different species, but intrafamily variation was also found. Heavier seeds contained less oil on a per gram basis than lighter seeds, suggesting a trade-off between seed weight and oil ratio in the seed and that oil storage strategy depends on seed size. Moreover, oily seeds contained more polyunsaturated FAs. However, contrary to our hypothesis, we did not found a higher antioxidant capability in oily seed extracts than in non-oily seeds, nor to the quantitative or to the qualitative variation of FAs in the seeds. Considering the role of these important trait variations on weed ecological strategies, such as germination period, seed predation rate and competition-colonisation trade-off, could improve the sustainable management of weed communities. [ABSTRACT FROM AUTHOR]

We build, calibrate and simulate a stylized energy-economy model designed to evaluate the magnitude of carbon tax that would allow the French economy to reduce by a factor of four its CO2 emissions at a forty-year horizon. We estimate the substitution possibilities between fossil energy and other factors for households and firms. We build two versions of the model, the first with exogenous technical progress, and the second with an endogenization of the direction of technical progress. We show that if the energy-saving technical progress rate remains at its recent historical value, the magnitude of the carbon tax is quite unrealistic. When the direction of technical progress responds endogenously to economic incentives, CO2 emissions can be reduced by more than that allowed by the substitution possibilities, but not by a factor of four. To achieve this, an additional instrument is needed, namely a subsidy to fossil energy-saving research. The redirection of technical progress, which is a driver of energy transition, comes at a small cost in terms of the overall growth rate of the economy. [ABSTRACT FROM AUTHOR]