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Torrefaction is a relatively new biomass pretreatment technology, which, over the past decades, has been recognized as a very promising and technically feasible method to improve the performance of biomass with regard to storage, handling, transportation and energy conversion processes (Tumuluru et al., 2011; Nhuchhen et al., 2014). Several demonstration plants have seen the light these years, but still a very few commercial plants are currently operating. Despite of the global efforts to develop torrefaction technology, there are still several technical challenges to be addressed in order to realize biomass torrefaction in an economically feasible way at a commercial scale (Chen et al., 2021; Nhuchhen et al., 2014). The major bottlenecks are nowadays the limited control of the process parameters (Brachi et al., 2018; Brachi et al., 2019), in particular the temperature, but the fuel flexibility (size distribution and moisture content) and scale-up of the system are often a barrier as well. In this Research Topic, the editorial team welcomed Original Research dealing with the latest advances in biomass upgrading through torrefaction, from both fundamental and practical points of view. The ultimate objective was to gain deeper insight into the biomass torrefaction to promote its technological development and commercialization. Specific themes covered in this research topic include: 1) the state-of-the-art and perspectives of the torrefaction technology; 2) the optimization of process parameters for a specific feedstock or end-use application (e.g., pyrolysis, adsorption of emerging pollutants, etc.); 3) the design and the process control in torrefaction technologies; and the 4) the chemistry and the reaction kinetics of biomass torrefaction. The articles were contributed by academics and researchers from various institutions in different countries including Canada, China, Belgium, Austria, United States, Taiwan and Brazil.

In this study, beryllium tiles from Joint European Torus (JET) vacuum vessel wall were analysed and compared regarding their position in the vacuum vessel and differences in the exploitation conditions during two campaigns of ITER-Like-Wall (ILW) in 2011–2012 (ILW1) and 2013–2014 (ILW2) Tritium content in beryllium samples were assessed. Two methods were used to measure tritium content in the samples – dissolution under controlled conditions and tritium thermal desorption. Prior to desorption and dissolution experiments, scanning electron microscopy and energy dispersive x-ray spectroscopy were used to study structure and chemical composition of plasma-facing-surfaces of the beryllium samples. Experimental results revealed that tritium content in the samples is in range of 2·10$^{11}$–2·10$^{13}$ tritium atoms per square centimetre of the surface area with its highest content in the samples from the outer wall of the vacuum vessel (up to 1.9·10$^{13}$ atoms/cm$^{2}$ in ILW1 campaign and 2.4·10$^{13}$ atoms/cm$^{2}$ in ILW2). The lowest content of tritium was found in the upper part of the vacuum vessel (2.0·10$^{12}$ atoms/cm$^{2}$ and 2.0·10$^{11}$ atoms/cm$^{2}$ in ILW1 and ILW2, respectively). Results obtained from scanning electron microscopy has shown that surface morphology is different within single tile, however if to compare two campaigns main tendencies remains similar.

Latent thermal energy storage systems represent a promising alternative to traditional sensible storages, but their exploitation requires a careful design of the system. The present paper reports a mathematical model for the simulation of thermal energy storage systems with phase change materials (PCMs). The model is suitable for the description of a latent heat storage using a fin-and-tube heat exchanger. Accuracy and computational effort are both taken into consideration, by coupling a 1D model for the tubes of the heat exchanger and a reduced 3D model for the material and fin domains. The developed model has been validated for two systems, realised at ITAE and ISE, differing for the PCM employed and the constructive characteristics of the heat exchanger. Results show that the model has a good accuracy and could predict the behaviour of the storages within 40 W error in case of powers and 1 K in case of heat transfer fluid temperatures. When a stable PCM was used, the average deviation between the PCM temperature in experiments and simulation was lower than 0.6 K.

In the present paper, infrared (IR) measurements were performed in order to study the development of injection and combustion in a transparent Euro 5 diesel engine operating in premixed mode. An elongated single cylinder engine equipped with the multi-cylinder head of commercial passenger car and with common rail (CR) injection system, respectively, was used. A sapphire window was set in the bottom of the combustion chamber, and a sapphire ring was placed between the head and the top of the cylinder line. Measurements were carried out through both accesses by a new high-speed infrared (IR) digital imaging system obtaining information that was difficult to achieve by the conventional UV- visible camera. IR camera was able to detect the emitted light in the wavelength range 1.5-5 ìm that is relevant for the emission bands of CO2 and H2O. The evaporation phase of pre and main injection, and subsequent combustion evolution were analyzed. Moreover, IR imaging was carried out by means of “ad hoc” filter to evaluate the spatial distribution of CO2 inside the cylinder. Images sequence during the whole engine cycle, starting from the intake and stopping to the exhaust phase, was observed from both optical windows. A comparison with visible imaging was carried out. IR measurements showed the ability to determine temporal and spatial distribution of fuel during evaporation phase and evaluate the combustion process evolution for longer time than visible imaging. Moreover, the IR camera was revealed very useful tool to detect the emitted light after a long operation time of the engine. The camera was able to acquire images of the reactions that happen in the combustion chamber and above the piston head even if the optical windows were obscured by the soot produced from the previous combustion cycles.

This study aimed to simulate oak and beech forest growth under various scenarios of climate change and to evaluate how the forest response depends on site properties and particularly on stand characteristics using the individual process-based model HETEROFOR. First, this model was evaluated on a wide range of site conditions. We used data from 36 long-term forest monitoring plots to initialize, calibrate, and evaluate HETEROFOR. This evaluation showed that HETEROFOR predicts individual tree radial growth and height increment reasonably well under different growing conditions when evaluated on independent sites. In our simulations under constant CO2 concentration ([CO2]cst) for the 2071-2100 period, climate change induced a moderate net primary production (NPP) gain in continental and mountainous zones and no change in the oceanic zone. The NPP changes were negatively affected by air temperature during the vegetation period and by the annual rainfall decrease. To a lower extent, they were influenced by soil extractable water reserve and stand characteristics. These NPP changes were positively affected by longer vegetation periods and negatively by drought for beech and larger autotrophic respiration costs for oak. For both species, the NPP gain was much larger with rising CO2 concentration ([CO2]var) mainly due to the CO2 fertilisation effect. Even if the species composition and structure had a limited influence on the forest response to climate change, they explained a large part of the NPP variability (44% and 34% for [CO2]cst and [CO2]var, respectively) compared to the climate change scenario (5% and 29%) and the inter-annual climate variability (20% and 16%). This gives the forester the possibility to act on the productivity of broadleaved forests and prepare them for possible adverse effects of climate change by reinforcing their resilience.

Global change, in particular climate change, will affect agriculture worldwide in many ways: increased drought or flooding amplitude and frequency, variable temperature increases, loss of natural depuration of waters, soil erosion, loss of soil carbon content, invasion by alien species, increased pest events, changes in plant phenology, increased sensitivity of crops to stress and diseases etc. (Fisher et al. 2005; Howden et al. 2007). These anticipated or even already occurring stresses raise concerns about the sustainability of production and the ability of agriculture to feed human populations. All these changes could lead to an increased use of pesticides (Kattwinkel et al. 2011). Moreover, demographic pressure continues to rise, in particular in tropical and sub-tropical regions, where greater threats to agriculture and food sustainability are anticipated by the Intergovernmental Panel on Climate Change (IPCC) (Easterling et al. 2007). These trends will certainly lead to mounting conflicts involving water uses (irrigation versus drinking water production or freshwater ecosystem maintenance, sanitation etc.) and food production. This appeals to an "ecologically intensive agriculture" (Griffon 2006), i.e. a sustainable agriculture providing ecosystem services more efficiently than today and causing fewer adverse impacts on the environment and water resources. With EU Directive 2009/128/EC (EC 2009a) enforcement, requesting Member States to adopt action plans aiming to reduce risks and impacts related to pesticide uses, there will be a focus in the public and political debates in Europe on achieving a more sustainable use of pesticides. This should consequently lead to a reduction of the risks or impacts of pesticides on the environment. In Europe, there is currently a strong focus on source (including dose) reduction. This approach may nevertheless be too restrictive if the goal is to reduce the agriculture footprint while maintaining or increasing yield. Depending on the chemical properties of pesticides as well as environmental factors, decreasing the amounts of pesticides applied to crops will not automatically produce a decrease in the risk to non-target species or water supply. How could society meet the challenge of the forthcoming climate change? What adaptations should be envisaged for agriculture/pesticide risk management (RM)? These changes will probably have a profound effect on agricultural systems (crop selection, farming practices etc.) and to a lesser extent influence the fate and effects of chemicals (Schiedek et al. 2007). These questions have been addressed by two European research networks, namely Euraqua (the European Network of Freshwater Research Organisations, http://www.euraqua.org/) and PEER (Partnership for European Environmental Research, http://www.peer.eu/), which organised a workshop aiming to identify research needs and strategies induced by these questions in October 2011 in Montpellier, France. The workshop's specific goals were to (1) discuss the pesticide risk assessment (RA) approach, its limitations (e.g.spatial scale and multi-stress situations), the connections between different policies (pesticide regulation and Water Framework Directive), the use of models, (2) review integrated practices and innovative technologies which could or are intended to reduce pesticides' environmental impacts and (3) contribute to the future research and development agenda. This review summarises the workshop discussions.

We break the barrier between simulation and experiment by comparing identical computed and experimental infrared observables.