There is an urgency within the building sector to reduce its greenhouse gas emissions and mitigate climate change. An increased proportion of biobased building materials in construction is a potential measure to reduce these emissions. Life cycle assessment (LCA) has often been applied to compare the climate impact from biobased materials with that from e.g. mineral based materials, mostly favouring biobased materials. Contradicting results have however been reported due to differences in methodology, as there is not yet consensus regarding certain aspects. The aim of this thesis is to study the implications from non-traditional practices in climate impact assessment of timber buildings, and to discuss the shortcomings of current practices when assessing such products and comparing them with non-renewable alternatives. The traditional practices for climate impact assessment of biobased materials have been identified, and then applied to a case study of a building with different timber frame designs and an alternative building with a concrete frame. Then, non-traditional practices were explored by calculating climate impact results using alternative methods to handle certain methodological aspects, which have been found relevant for forest products in previous research such as the timing of emissions, biogenic emissions, carbon storage in the products, end-of-life substitution credits, soil carbon disturbances and change in albedo. These alternative practices and their implications were also studied for low-carbon buildings. The use of non-traditional practices can affect the climate impact assessment results of timber buildings, and to some extent the comparison with buildings with lower content of biobased building materials. This effect is especially evident for energy-efficient buildings. Current normal practices tend to account separately for forest-related carbon flows and aspects such as biogenic carbon emissions and sequestration or effects from carbon storage in the products, missing to capture the forest carbon cycle as a whole. Climate neutrality of wood-based construction materials seems like a valid assumption for studies which require methodological simplification, while other aspects such as end-of-life substitution credits, soil carbon disturbances or changes in albedo should be studied carefully due to their potentially high implications and the uncertainties around the methods used to account for them. If forest phenomena are to be included in LCA studies, a robust and complete model of the forest carbon cycle should be used. Another shortcoming is the lack of clear communication of the way some important aspects were handled. / <p>QC 20150310</p>

An animal’s ability to navigate through its natural environment is critical to its survival. Navigation can be slow and methodical such as an annual migration, or purely reactive such as an escape response. How sensory input is translated into a fast behavioral output to execute goal oriented locomotion remains elusive. In this dissertation, I aimed to investigate escape response behavior in the nematode C. elegans. It has been shown that the biogenic amine tyramine is essential for the escape response. A tyramine-gated chloride channel, LGC-55, has been revealed to modulate suppression of head oscillations and reversal behavior in response to touch. Here, I discovered key modulators of the tyraminergic signaling pathway through forward and reverse genetic screens using exogenous tyramine drug plates. ser-2, a tyramine activated G protein-coupled receptor mutant, was partially resistant to the paralytic effects of exogenous tyramine on body movements, indicating a role in locomotion behavior. Further analysis revealed that ser-2 is asymmetrically expressed in the VD GABAergic motor neurons, and that SER-2 inhibits neurotransmitter release along the ventral nerve cord. Although overall locomotion was normal in ser-2 mutants, they failed to execute omega turns by fully contracting the ventral musculature. Omega turns allow the animal to reverse and completely change directions away from a predator during the escape response. Furthermore, my studies developed an assay to investigate instantaneous velocity changes during the escape response using machine based vision. We sought to determine how an animal accelerates in response to a mechanical stimulus, and subsequently decelerates to a basal locomotion rate. Mutant analysis using this assay revealed roles for both dopamine and tyramine signaling. During my doctoral work, I have further established the importance for tyramine in the nematode, as I have demonstrated two additional roles for tyramine in modulating escape response behavior in C. elegans.

The mining, processing, and use of finite natural resources is associated with significant interventions in the natural environment. Thus, these and other negative consequences make it necessary to reduce resource consumption. An important field of action is the more efficient use of biogenic residues as secondary raw materials. However, high water containing biomasses are still a problem since they need an energy- and cost-intensive pre-treatment for many conversion processes, which can make their use uneconomical. Hydrothermal processes (HTP) seem to be promising, since they require an aqueous environment for optimal processing anyway. Although technological progress within the industry is recognisable, however, to date HTP have not been established in industrial continuous operation in Germany. The core of this work is identifying reasons for this sluggish development and deriving appropriate recommendations for action. Based on the hypothesis that HTP can contribute to the efficient utilisation of biogenic residues in the future, potentials and obstacles for the development of HTP in Germany are identified using a literature review, expert survey, expert workshop, and SWOT analysis. To estimate the future potential of HTP in a systematic and structured way, a multi-criteria technology assessment approach is developed based on the results. To this end, assessment criteria for HTP are derived, weighted by expert judgment, and integrated into a transparent and structured procedure. In addition, mainly based on a Delphi-survey key factors of HTP development by 2030 in Germany are identified and three development alternatives for HTP in Germany by 2030 are derived. Using a system analysis and a comparative multi-criteria analysis at plant level, these scenarios are analysed for their possible future impact. Based on this methodology, the work shows that the production costs for the end products, the energy efficiency of the process, and the proportion of recycled phosphorus are of high relevance to the techno-economic success of HTP compared to reference systems, and they are therefore of high importance for its future development on the plant level. In addition, further key factors for the future development of HTP in Germany on the system level are found to be mainly in the political-legal (e.g. legal waste status of products from HTP) and techno-economic (e.g. cost-effective process water treatment) areas. According to this, important fields of action are the identification and use of cost reduction potentials (e.g. heat waste use), the development of system integrated decentralised plant concepts with integrated nutrient recycling (e.g. phosphorus), and the development of cost-effective ways to treat process water. System integration, cost-effective process water treatment, and nutrient recycling are all closely linked to production costs, investment costs, and potential revenues, and can contribute to improved process economics. For these areas, there is promising future potential to achieve higher competitiveness with reference technologies that are currently more economical.:Bibliographic description Curriculum Vitae Selbstständigkeitserklärung Danksagung List of Publications Contribution to the Publications Contents List of Acronyms List of Tables List of Figures Part I Introductory Chapters 1 Introduction and Background Hydrothermal processes: Introduction and status quo State of the art in the research field and knowledge gaps Objective and research framework Expected value added of this work 2 Materials and methods Derivation of HTP evaluation metrics and technology assessment tool Derivation of key HTP development factors and scenarios Performing the system-level scenario analysis Plant-level scenario analysis and test application of the assessment tool Derivation of core recommendations 3 Results and discussion Key development factors for HTP in Germany and scenarios System-level scenario analysis Test application of the assessment tool on plant level scenarios Recommendations Discussion 4 Conclusion and outlook Future research Further fields for the application of the developed methods 5 References Part II Appended Articles Paper I Paper II Paper III Paper IV Paper V Paper VI / Der Abbau, die Verarbeitung und die Nutzung endlicher natürlicher Ressourcen sind mit erheblichen Eingriffen in die natürliche Umwelt verbunden. Diese und andere negative Folgen machen es daher erforderlich, den Ressourcenverbrauch zu senken. Ein wichtiges Handlungsfeld ist die effizientere Nutzung biogener Reststoffe als Sekundärrohstoffe. Stark wasserhaltige Biomassen sind jedoch ein Problem, da sie für viele Umwandlungsprozesse eine energie- und kostenintensive Vorbehandlung benötigen, was ihre Verwendung unwirtschaftlich machen kann. Hydrothermale Prozesse (HTP) scheinen für diese Reststoffe allerdings vielversprechend zu sein, da sie ohnehin eine wässrige Umgebung für eine optimale Verarbeitung benötigen. Obwohl der technologische Fortschritt innerhalb der Branche erkennbar ist, wurde HTP in Deutschland bisher nicht im industriellen Dauerbetrieb etabliert. Der Kern dieser Arbeit besteht darin, Gründe für diese schleppende Entwicklung zu ermitteln und geeignete Handlungsempfehlungen abzuleiten. Basierend auf der Hypothese, dass HTP in Zukunft zur effizienten Nutzung biogener Reststoffe beitragen können, werden Potenziale und Hindernisse für deren Entwicklung in Deutschland anhand einer Literaturrecherche, einer Expertenumfrage, eines Expertenworkshops und einer SWOT-Analyse ermittelt. Um das zukünftige Potenzial von HTP systematisch und strukturiert abzuschätzen, wird basierend auf den Ergebnissen ein multi-kriterieller Technologiebewertungsansatz entwickelt. Zu diesem Zweck werden Bewertungskriterien für HTP abgeleitet, nach Expertenmeinung gewichtet und in ein transparentes und strukturiertes Verfahren integriert. Darüber hinaus werden hauptsächlich auf der Grundlage einer Delphi-Umfrage Schlüsselfaktoren für die HTP-Entwicklung bis 2030 in Deutschland identifiziert und drei Entwicklungsalternativen für HTP in Deutschland bis 2030 abgeleitet. Mithilfe einer Systemanalyse und einer vergleichenden multi-kriteriellen Analyse auf Anlagenebene werden diese Szenarien auf ihre möglichen zukünftigen Auswirkungen hin analysiert. Basierend auf dieser Methodik zeigen sich als Ergebnisse, dass die Produktionskosten für die Endprodukte, die Energieeffizienz der Prozesse und der Anteil an recyceltem Phosphor für den techno-ökonomischen Erfolg von HTP im Vergleich zu Referenzsystemen von hoher Relevanz und daher auch von hoher Bedeutung für die zukünftige Entwicklung auf Anlagenebene sind. Darüber hinaus liegen weitere Schlüsselfaktoren für die künftige Entwicklung von HTP in Deutschland auf Systemebene hauptsächlich im politisch-rechtlichen (z. B. legalen Abfallstatus von Produkten aus HTP) und techno-ökonomischen (z. B. kostengünstige Prozesswasseraufbereitung)) Bereichen. Wichtige Handlungsfelder sind demnach die Ermittlung und Nutzung von Kostensenkungspotentialen (zB Abwärmenutzung), die Entwicklung systemintegrierter dezentraler Anlagenkonzepte mit integriertem Nährstoffrecycling (z.B. Phosphor) und die Entwicklung kostengünstiger Wege zur Prozesswasserbehandlung. Systemintegration, kostengünstige Prozesswasseraufbereitung und Nährstoffrecycling hängen eng mit Produktionskosten, Investitionskosten und potenziellen Einnahmen zusammen und können zu einer verbesserten Wirtschaftlichkeit der Prozesse beitragen. Für diese Bereiche besteht ein vielversprechendes Zukunftspotenzial für eine höhere Wettbewerbsfähigkeit zu Referenztechnologien, die derzeit noch wirtschaftlicher sind.:Bibliographic description Curriculum Vitae Selbstständigkeitserklärung Danksagung List of Publications Contribution to the Publications Contents List of Acronyms List of Tables List of Figures Part I Introductory Chapters 1 Introduction and Background Hydrothermal processes: Introduction and status quo State of the art in the research field and knowledge gaps Objective and research framework Expected value added of this work 2 Materials and methods Derivation of HTP evaluation metrics and technology assessment tool Derivation of key HTP development factors and scenarios Performing the system-level scenario analysis Plant-level scenario analysis and test application of the assessment tool Derivation of core recommendations 3 Results and discussion Key development factors for HTP in Germany and scenarios System-level scenario analysis Test application of the assessment tool on plant level scenarios Recommendations Discussion 4 Conclusion and outlook Future research Further fields for the application of the developed methods 5 References Part II Appended Articles Paper I Paper II Paper III Paper IV Paper V Paper VI

oundry production, which forms an integral part of the engineering industry, is a source of waste with a negative impact on the working and living environment. The pressure on greening the production in all production branches of industry does not dodge the foundry industry and technical engineers seek out possibilities of decreasing the negative impact of the production of casting on the environment. An important source of environmentally dangerous waste in foundry operation is the use of organic compounds during the preparation of shaping and core mixtures. Their substitution with materials that would ensure similar technological features of the shaping and core mixtures as the organic materials used hitherto and at the same time decrease the amount of solid, liquid and gaseous ecologically undesirable compounds used in or arising during the preparation and use of shaping and core mixtures, would be significant for decreasing the ecological burden connected to casting production. A promising group of materials usable as components of shaping and core mixtures are the biopolymer materials which can substitute the organic connective systems used in the production of foundry cores by the means of the so-called hot processes – Hot-Box and Warm-Box. This work focuses on the exploration of the technological and ecological features of several biopolymer materials available on the domestic market which have the potential to become a full alternative of the binders used so far on the basis of urea-formaldehyde, melamine-formaldehyde, phenol-formaldehyde and furan resins.

No description available.

This doctoral work was developed in the frame of bone tissue engineering, dealing with the fabrication of scaffolds for the regeneration of bones. At this purpose, calcium phosphates derived from natural sources are very interesting because they are more similar to the bone mineral and possess better bioactivity. Indeed, the bone mineral is different from synthetic hydroxyapatite as it is non-stoichiometric, nanosized, it presents a high degree of disorder and contains many additional ions and impurities such as CO32-, Mg2+, Sr2+, Na+, etc. These characteristics can be easily obtained by synthesizing hydroxyapatite from natural sources, such as corals, starfishes, seashells, animal bones, bird eggshells etc. The natural sources used in the present work are three types of biogenic calcium carbonate, i.e. calcium carbonate that is produced by living organisms in the form of aragonite or calcite. Among the different sources, three biogenic calcium carbonates were chosen: cuttlefish (Sepia Officinalis) bones, mussel (Mytilus Galloprovincialis) shells and chicken eggshells. Besides their abundance and availability, they were selected because of their different composition: aragonite in cuttlebones, calcite in eggshells and a mixture of aragonite and calcite in mussel shells. After the first chapter, which is a theoretical introduction, this thesis is divided into other five chapters. Chapter 2 contains a careful characterization of the three biogenic raw materials while Chapter 3 deals with the synthesis of hydroxyapatite starting from these natural sources. The process developed here takes place entirely at nearly room temperature, which allows the organic part of the biological materials to be preserved. This synthesis process is basically a wet mechanosynthesis followed by a mild heat treatment (up to 150°C). The study focuses on the influence of several process parameters on the synthesis efficiency: temperature, milling time, pH and raw material. The temperature used to dry the slurry after the wet ball-milling was found to be the most important parameter, the higher the temperature the faster the conversion of CaCO3 into hydroxyapatite. Moreover, aragonite was found to transform more easily into hydroxyapatite with respect to calcite, and also to follow a different reaction path. The synthesis process described in Chapter 3 allowed to produce different bio-derived powders that were found to be non-stoichiometric, nanosized, carbonated hydroxyapatites, containing also additional ions, especially Mg2+ in the eggshell-derived material and Sr2+ in the cuttlebone-derived one. These powders were then used as a starting point for the studies presented in the next three chapters. Chapter 4 shows a very preliminary evaluation of the interaction with human cells in vitro. First, the as-synthesized powders were consolidated by uniaxial pressing and sintering at temperatures between 900°C and 1100°C and their crystallographic composition was analyzed. Then, after having established the non-cytotoxicity of the sintered pellets, osteoblasts from human osteosarcoma cell line were seeded on the pellets and their behavior after 1, 3 and 5 days of culture was observed by confocal microscopy. In general, all materials promoted good cell adhesion and proliferation, especially the eggshell-derived one. At this point, the bio-derived materials were found to induce a good cellular response but, in order to foster the regeneration of bones, a scaffold must also contain a large amount of interconnected porosity. Among the numerous methods to fabricate porous structures, additive manufacturing is surely very attractive due many advantages, such as the possibility of customizing the shape based on tomography images from the patients, the fact that no mold is needed and the freedom of fully designing the porosity. Indeed, not only the size and the amount of porosity are important, but also the shape of the pores and their position and orientation have a deep effect on the interaction with the cells. Therefore, Chapter 5 and Chapter 6 deal with the fabrication of scaffolds by 3D printing, following two different approaches. In the study presented in Chapter 5, the powders synthesized from cuttlebones, mussel shells and eggshells were used in combination with a thermoplastic polymer (PCL, polycaprolactone) to obtain bioactive composites. Composite materials made of 85 wt% PCL and 15 wt% bio-derived hydroxyapatite were used to fabricate porous scaffolds by extrusion 3D printing. The biological in vitro tests showed that the composite scaffolds possess better bioactivity than the pure PCL ones, especially those containing mussel shell- and cuttlebone-derived powders, which promoted the best cell adhesion, proliferation and metabolic activity of human osteosarcoma cells after 7 days of culture. In addition, the elastic compressive modulus, which was found to be between 177-316 MPa, thus in the range of that of trabecular bone, was found to increase of about ∼50% with the addition of the bio-derived nanopowders. Finally, in Chapter 6, the cuttlebone-derived powder was used to fabricate porous bioceramic scaffolds by binder jetting 3D printing. Due to serious technical issues related to the printing of a nanosized powder, 10 wt% of bio-derived powder was mixed with a glass-ceramic powder with bigger particle size. Moreover, the organic part of the cuttlebone had to be previously eliminated by a heat treatment at 800°C. Thanks to the great freedom of design that is allowed by the binder jetting process, scaffolds with two different pore geometries were fabricated: with pores of uniform size and with a size-gradient. Indeed, natural bone possesses a gradient in porosity from the core to the surface, from porous trabecular bone to dense cortical bone. The sintered scaffolds showed a total porosity of ∼60% for the pure glass-ceramic and ∼70% for the glass-ceramic with 10 wt% of cuttlebone-derived nanoparticles, which most probably slowed down the densification by limiting the contact between the glassy particles. All the bioceramic scaffolds promoted good adhesion and proliferation of human bone marrow-derived mesenchymal stem cells in vitro, without any significant difference between the different samples. However, the scaffolds with the cuttlebone-derived powder and with gradient porosity showed the greatest decrease of metabolic activity after 10 days of culture, which could be accounted as a sign of differentiation of stem cells.

The aim of this work is to test the proposed approach of algal scavenging as a driver of sediment mercury (Hg) on different time scales and to gain a better understanding of the mechanisms of Hg accumulation in lake sediments. A 3000-year sediment record from Nylandssjön in northern Sweden was analysed for this purpose, as well as a 20-year sediment record from the seasonal sediment traps of this lake. The diatom proxy biogenic silica (bSi) was determined by Fourier transform infrared spectroscopy (FTIRS) and chlorophyll-a (Chl-a) as a proxy for primary productivity by non-destructive visible near-infrared reflectance spectroscopy (VNIRS). Silica, normalised to minerogenic matter by aluminium (Si/Al) as an indirect diatom proxy and other geochemical parameters were analysed by the non-destructive method of X-ray fluorescence spectroscopy (XRF). The Hg content in the sediment was determined using the the thermal decomposition atomic absorption spectrophotometers (TD-AAS) method. Over the different time scales, organic matter (OM) is an important control factor for Hg, which in turn was strongly associated with primary productivity. Hg was normalised against OM by determining the Hg/LOI or Hg/C ratios. No positive correlation was found between the normalised Hg ratios and the proxies of primary productivity (bSi, Chl-a and Si/Al). Negative correlations between OM and minerogenic elements coinciding with human-induced erosion events and increasing Hg levels in the sediment were found. This is true, both for the long-term record in the sediment cores and the high-resolution data from the sediment traps. Furthermore, in the seasonal sediment record of the sediment traps, in-lake processes like lake turnover in spring and autumn could be linked to precipitation of iron oxyhydroxides (FeOOH) and increasing sedimentary Hg. This may be supported by the parallel sediment accumulation of other metals like nickel (Ni) and zinc (Zn) at the time of the lake turnover.

[pt] Uma sonda fotoluminescente do tipo turn-on foi avaliada para a detecção de putrescina usando pontos quânticos de grafeno (GQDs). Diferentes nanopartículas de carbono fotoluminescentes foram preparadas usando a abordagem bottom-up, usando ácido cítrico como precursor, sozinho ou misturado com outros compostos contendo heteroátomos (N e/ou S) visando funcionalização da nanoestrutura. Observou- se que as nanopartículas preparadas com ácido cítrico e tioureia (GQDs-TU) apresentaram melhor perfil aumento da fotoluminescência (resposta analítica) na presença dessa amina biogênica. As condições experimentais foram ajustadas para o melhor perfil de resposta e para obter os parâmetros analíticos de mérito. No ensaio em batelada, a curva analítica normalizada (concentração L-L0 versus PUT) foi linear (R2 = 0,9498) até 90 mg L1 . O limite de quantificação (LOQ) foi de 15,1 mg L-1 e o limite de detecção (LOD) foi de 4,5 mg L-1 . Além disso, a estratégia proposta para a determinação indireta de putrescina foi adaptada para um sistema de análise por injeção em fluxo (FIA) a fim de aumentar a frequência analítica, diminuir os resíduos e automatizar a quantificação do analito. Após a otimização do ensaio, com a faixa linear cobrindo o intervalo até 50 mg L-1 (R2 = 0,9980), os valores de LOD e LOQ foram 3,0 mg L1 e 9,9 mg L-1 , respectivamente. / [en] A photoluminescent turn-on probe was evaluated for putrescine detection using graphene quantum dots (GQDs). Different photoluminescent carbon nanoparticles were prepared using a bottom-up approach, employing citric acid as a precursor, either alone or mixed with other compounds containing heteroatoms (N and/or S) for nanostructure functionalization. It was observed that the nanoparticles prepared with citric acid and thiourea (GQDs-TU) exhibited a more pronounced increase in photoluminescence (analytical response) when exposed to this biogenic amine. Experimental conditions were fine-tuned to optimize the response profile and obtain the analytical parameters of merit. In the batch assay, the normalized analytical curve (L-L0 concentration versus PUT) was linear (R2 = 0,9498) up to 90 mg L-1 . The limit of quantification (LOQ) was 15,1 mg L-1 and the limit of detection (LOD) was 4,5 g L-1 . Furthermore, the proposed strategy for the indirect determination of putrescine was adapted for a flow injection analysis (FIA) system to increase the analytical frequency, reduce waste, and automate analyte quantification. After optimization of the assay, with the linear range covering the range up to 50 mg L-1 (R2 = 0,9980), the LOD and LOQ values were 3,0 mg L-1 e 9,93 mg L-1 , respectively.

To date, most of the sewage treatment plants of the cities are in poor condition, the structures need to be reconstructed in order to ensure wastewater treatment up to the indicators required by regulatory documents. The paper describes in detail the existing technological scheme of treatment facilities. As a result of the analysis of the operation of existing structures, a scheme with the removal of biogenic elements and modern sludge treatment technology was proposed. The project provides for the use of existing facilities and networks. The paper outlines what reconstruction involves. / На сегодняшний день большая часть очистных сооружений хозяйственно-бытовой канализации городов находится в неудовлетворительном состоянии, сооружения нуждаются в проведении реконструкции, чтобы обеспечивать очистку сточных вод до требуемых нормативными документами показателей. В работе подробно описана существующая технологическая схема очистных сооружений. В результате анализа работы действующих сооружений была предложена схема с удалением биогенных элементов, современной технологией обработки осадка. Проект предусматривает использование существующих сооружений и сетей. В работе изложено, что предполагает реконструкция.

Les Composés Organiques Volatils biogènes (COVB) sont des molécules issues du métabolisme secondaire des végétaux, dont l'émission peut être modulée par les conditions environnementales. Parmi ces composés, l'isoprène a été très étudié du fait des flux d'émission important et de son implication dans la photochimie troposphérique. Cependant, les mécanismes d'action des facteurs environnementaux sont encore mal connus, et notamment celui de l'impact du stress hydrique. Dans le contexte de changements climatiques, ce type de stress va particulièrement impacter la région méditerranéenne.Nous avons étudié l'impact du stress hydrique sur les émissions d'isoprène de Quercus pubescens Willd. Cette espèce, très présente dans cette région, serait la seconde source d'isoprène en Europe.Deux étude ont été menées.La première, effectuée en pépinière, a consisté à appliquer un stress hydrique modéré et sévère d'avril à octobre. Une augmentation des émissions d'isoprène des arbres modérément stressés a été observée alors qu'il n'y a eu aucune modification des émissions pour les arbres très stressés.La seconde a consisté à faire un suivi saisonnier du stress hydrique au sein d'une chênaie pubescente. Un stress hydrique amplifié a été appliqué par un système d'exclusion de pluie, permettant de diminuer la quantité de pluie de 30%. Nous avons observé que le stress hydrique amplifié augmentait les facteurs d'émission d'isoprène des arbres.Cette base de données a permis le développement, par Réseau de Neurones Artificiels (RNA), d'un algorithme d'émission d'isoprène. Nous avons ainsi mis en évidence l'impact prédominant du contenu en eau du sol sur les émissions d'isoprène. / Biogenic Volatile Organic Compounds (BVOC) are plants secondary-metabolism-molecules. Their emissions are modulated by environmental conditions. Among these compounds, isoprene has been particularly studied due to its intense emission fluxes as well as its major contribution to tropospheric photochemistry. However, the impacts of environmental constraints on isoprene emission are still not yet well known. In particular, water stress impact is still a contradictory issue. In a world facing multiple climatic changes, models expect this kind of stress to hit Mediterranean area.This work focused on the impact of water stress on Quercus pubescens Willd. isoprene emissions. This species, widely spread in this area, is the second isoprene emitter in Europe.Two types of study were used.First, during an experimental carried out in a nursery, Q. pubescens saplings were grown under a moderate and severe water stress from April to October. This experimentation highlighted an increase of isoprene emissions for mid-stressed trees, while no emission changes were observed for the highly stressed trees.Secondly, an experimentation was conducted on a pubescent oak forest with trees acclimated to long lasting stress periods. We followed, during a whole season, the impact, on isoprene emissions, of a water stress created by artificially reducing 30% of the rains by means of a specific deploying roof. Isoprene emission factors were observed to increase under water stress.The database thus obtained was used in an Artificial Neural Network (ANN) to develop an appropriate isoprene emission algorithm. We underlined the predominant impact of soil water content on isoprene emissions.