The thesis occupies with the use of hemp in cosmetics and in food processing. In the theoretical part hemp was characterized by the content of active substances. In the experimental part the thesis is concerned with characterization of two different hemp varieties Carmagnola and Ferimon in terms of presence of active substances. The next part focuses on preparation of cosmetic with hemp content. In cosmetic preparations and in the extracts the inhibitory effect against Propionibacterium acnes, Micrococcus luteus, Escherichia coli and Candida glabrata was tested. The content of fatty acids and vitamin E was determined in hemp seed. The results show that dried hemp flower extract contains the largest amount of active substances and has the greatest inhibitory effect against all tested bacteria except Candida there was no effect. Cosmetic preparations did not show almost any inhibitory effect because of low concentration of active substances. The hemp seed contained high amount of PUFA and essential fatty acids. Vitamin E was found out in all of three hemp oils.

En s’appuyant sur les démarches récentes en palynologie appliquée à l’histoire rurale, la thèse pose trois objectifs : (1) questionner la chronologie des essors et déprises des paysages agropastoraux du nord de la Haute-Bretagne entre le XIe et le XVIe siècle, (2) réfléchir à l’originalité de ce secteur par rapport aux territoires environnants, (3) analyser le poids descontextes économiques et sociaux sur l’aménagement des paysages. Les dynamiques des paysages agropastoraux mettent en évidence une chronologie classique pour le début de la période. Un essor de la croissance touche l’ensemble du secteur aux XIe-XIIe s. Cet essor amène progressivement à une situation de blocage à partir du XIIIe s. Ces dynamiques se transcrivent dans les pratiques. On observe un glissement de pratiques de cultures temporaires et de prairies gérées extensivementà une intensification progressive des activités agricoles. L’originalité concerne les crises des XIVe-XVe s. qui ne sont perçues qu’à proximité de la frontière normande. Le secteur de Rennes est concerné par un dynamisme agricole qui prend la forme d’une intensification de la céréaliculture, avec la mise en place d’un système de rotation intégrant la culture du sarrasin. Ce changement dans les pratiques agropastorales est peut-être une réponse au blocage de la croissance. Il est surtout permis par le dynamisme économique qui touche le duché de Bretagne aux XIVe-XVe s. La croissance n’atteint la frontière normande qu’à compter de la seconde moitié du XVe s. Ce décalage s’observe également dans la production de chanvre textile qui a marqué les paysages des campagnes de Haute-Bretagne. Les données polliniques interrogent ainsi l’origine des zones de production de toiles connues à l’époque moderne. / Based on recent approaches in pollen analysis applied to rural history, this PhD dissertation has three objectives: (1) to question the chronology of agrarian expansion and regression in northern Upper Brittany between 11th and 16th century; (2) to ponder the originality of this area in relation to the surrounding areas; (3) to analyze the weight of economic and socialcontexts on the construction of landscapes. The changes in agro-pastoral landscapes reveal a rather classical chronology for the beginning of the period. The agricultural expansion affects the whole area in the 11th and 12th centuries. This expansion gradually leads to a stalling of growth in the 13th century. These changes affected practices. Thus we observe a shift from practices of temporary crops and extensively-managed grasslands towards a gradual intensification of agricultural activities. The originality concerns the late medieval agrarian crisis which is only detected close to the Norman border. The area of Rennes, on the other hand, is affected by an agricultural expansion which takes the form of an intensification of cereal farming, with the introduction of a new system of crop rotation integrating the cultivation of buckwheat. This change in agro-pastoral practices may be an answer to the stalling of growth. This change is mainly allowed by the economic dynamism that affects the duchy of Brittany in the 14th and 15th centuries. Growth doesn’t reach the Norman border until the second half of the 15th century. This time-lag can also be seen in the production of bastfibres of hemp which transformed the landscapes of rural Upper Brittany. Thus the palynological analysis questions the origin of the areas of production of canvases known in early modern times.

Textilindustrin räknas till en av de största industrierna i världen och står för ett antal utmaningar gällande miljöfrågor. En utav anledningarna till att textilindustrin måste ställa om är användandet av konventionell bomull. Konventionell bomull odlas med bekämpningsmedel som innehåller kemikalier som skadar omgivande vatten och mark. Bomull är även begränsad till att växa i subtropiska klimat där det råder brist på vatten. Bomullens negativa påverkan på miljön har startat en jakt på alternativa fibrer, vilket är anledningen till ett ökat intresse för hampa (Cannabis Sativa L.) har skapats. Hampa kan odlas utan bekämpnings- och ogräsmedel, behöver mindre vatten än bomull och kan växa i alla typer av klimat. Hampa är ett starkt material som har en lång historia av textil applikation över hela världen, men på grund av associeringen till droger har det gjort plantan kontroversiell och den har därtill varit olaglig att odla. Förbudet resulterade i att hampaindustrin stodstill och förhindrade innovation, forskning och teknisk utveckling som medförde en brist på kunskap gällande hanteringen av hampafibern. Idag är det lagligt att odla hampa om den faller underindustrihampa. För att kunna studera detta material på ett mer ingående (och hanterbart) sätt har denna uppsats valt att granska användningen av hampa i denim, vilket utgör ett av textilindustrins mest populära textiler. En djupgående kvalitativ fallstudie på användandet av hampa i just denim utfördes genomdatainsamling av tidigare forskning och intervjuer. Resultatet av studien visade att hampa kan vara ett passande och mer miljövänligt ersättningsmaterial i produktionen av denim i jämfört medkonventionell bomull som föredras idag, främst på grund av en minskad miljöpåverkan i odlingsfasen. Att ersätta bomullsfibern helt i denim är dock svårt att uppnå, men med hjälp av ökade investeringar i beredningsfasen och en högre efterfrågan av hampafibern ses detta som en möjlighet. Genom att fokusera på fiberns miljövänliga egenskaper och se bort från stigmatiseringen är hampa ett passande material för hållbar utveckling. Studien utgör därmed ett värdefullt bidrag i resan moten mer miljövänlig textilindustri. / The textile industry is considered to be one of the largest industries in the world and faces a number of challenges regarding environmental issues; the continued use of conventional cotton makes for one such challenge. Cotton is grown using both pesticides and insecticides that harm surrounding waters and soils. Cotton is also limited to growing in subtropical climates where water scarcity prevails. These negative impacts have necessitated in a need for alternative fibers. Hemp (Cannabis Sativa L.) has become one such fiber. Hemp can be cultivated without pesticides, insecticides and herbicides, need less water than cotton and can grow in any type of climate. Hemp is a durable material with a long history within textile application globally. However, its association with narcotics has made the crop controversial, and its partial prohibition has lead to prevented innovation, research, and technological development surrounding the hemp industry, ultimately creating an underdeveloped manufacturing process. Today it is legal to cultivate hemp if it is approved as an industrial hemp. In order to study hemp in a more manageable way, this study aims to investigate the usage of hemp in denim, specifically, which is one of the most popular textiles in the textile industry. An in-depth qualitative case study on the usage of hemp in denim has therefore been conducted through data gathering from previous research and through interviews. The results of this study showed that hemp can be a suitable and more sustainable replacement material in the manufacturing of denim compared to the conventional cotton favored today, due to a reduced environmental impact throughout the cultivation and growing process. A full replacement of the cotton fiber in denim remains difficult to achieve. However, increased investments in the manufacturing phase and higher demand of the crop can make this a reality. By focusing on the environmentally friendly properties of the hemp fiber and avoiding its stigma, hemp remains a useful and suitable material for sustainable development. Thus, this study makes a valuable contribution in the journey towards a more environmentally friendly textile industry.

More sustainable and efficient degumming methods are required to extract finner bast fibres, especially from agro-industrial waste streams such as stalks from hemp for food purposes. For this reason, in this study, two urea-based treatments were evaluated as degumming alternatives for unretted hemp fibres from residual streams, one at cold and alkaline conditions (CUA) and the other in combination with microwave radiation (MWU). Both approaches reduced fiber bundles diameter, decreasing 61% at -7°C 5 minutes, 12%Urea-5%NaOH, and 44% for microwave-30%urea for 30 minutes. Although both methods resulted in considerable fibre bundle diameter reduction, they resulted in a lower reduction than the 74% obtained for a traditional alkali (TA) degumming. Shorter fibres were obtained after the treatments. CUA and TA treatments obtained similar fibre lengths, while MWU resulted in longer than the other treatments. The chemical and thermal analysis showed that the highest removal of no cellulosic components was achieved by the TA treatment, followed by CUA and MWU. The treatments were applied to nonwovens produced by needle punching, showing no significant differences in tenacity and flexural rigidity compared to non-treated nonwovens. An increase of mass per unit area was identified for the CUA-treated fabrics, attributed to crimp generated in the treatment. Both urea-based treatments showed potential as more sustainable alternatives for degumming unretted hemp fibre bundles extracted from agro-waste.

No description available.

For the first time in many decades, a hemp pilot program was initiated in Virginia in 2016. Outdoor surveys were conducted in the 2017 and 2018 field seasons to record insect presence and feeding injury to plants. Multiple insect pests were present, including corn earworm (Helicoverpa zea [Boddie]) (Lepidoptera: Noctuidae), brown marmorated stink bug (Halyomorpha halys [Stål]) (Hemiptera: Pentatomidae), and cannabis aphid (Phorodon cannabis) (Hemiptera: Aphididae). In 2019, indoor production surveys revealed that cannabis aphid, twospotted spider mite (Tetranychus urticae Koch) (Acari: Tetranychidae), and hemp russet mite (Aculops cannabicola [Farkas]) (Acari: Eriophyidae) would likely cause production issues. Very little is known about the impact of insect defoliation in hemp so studies were conducted in 2018-2020 to determine impacts on yield and cannabinoid content of grain and cannabinoid variety hemp due to leaf surface area loss. In Virginia over two growing seasons, manual removal of leaf tissue in grain and CBD cultivars did not significantly impact observable effects on physical yield (seed or bud weight) or cannabinoid content (CBD or THC) at time of harvest. Corn earworm is the major pest of hemp produced outdoors and studies occurred to evaluate monitoring and management strategies. Pheromone traps may be valuable in determining when corn earworm moths are present in the vicinity of hemp fields but are not useful in predicting larval presence in buds or final crop damage. Larval presence and final crop damage are related. Brown marmorated stink bug does not appear to be a concern in hemp, at least at this time. / Doctor of Philosophy / For the first time in many decades, a hemp pilot program was initiated in Virginia in 2016. Outdoor surveys were conducted in the 2017 and 2018 field seasons to record insect presence and feeding injury to plants. Multiple insect pests were present, including corn earworm, brown marmorated stink bug, and cannabis aphid. In 2019, indoor production surveys revealed that cannabis aphid, twospotted spider mite, and hemp russet mite would likely cause production issues. Very little is known about the impact of leaf area loss due to insect feeding in hemp so studies were conducted in 2018-2020 to determine impacts on yield and cannabinoid content of grain and cannabinoid variety hemp due to leaf surface area loss. In Virginia over two growing seasons, manual removal of leaf tissue in grain and CBD cultivars did not significantly impact observable effects on physical yield (seed or bud weight) or cannabinoid content (CBD or THC) at time of harvest. Corn earworm is the major pest of hemp produced outdoors and studies occurred to evaluate monitoring and management strategies. Pheromone traps may be valuable in determining when corn earworm moths are present in the vicinity of hemp fields but are not useful in predicting larval presence in buds or final crop damage. Larval presence and final crop damage are related. Brown marmorated stink bug does not appear to be a concern in hemp, at least at this time.

In response to the challenge of moving society toward sustainability, a paradigm shift within the materials sector calls for a transition focusing on the socio-ecological sustainability of natural materials such as industrial hemp fibre (Cannabis sativa L.). Although well-suited for hemp cultivation, Sweden faces challenges building its hemp fibre value chain (HFVC). Taking a systems perspective, this study aimed to identify how Sweden can strengthen its HFVC by 1) uncovering system dynamics and mapping out the current HFVC and 2) identifying interventions that could strengthen the system. This study used Meadows’ 12 Leverage Points concept to analyse the data from survey-based questionnaires and semi-structured interviews with HFVC actors. The results illuminated a systemic view of the current structure of the HFVC and suggested a set of interventions for ‘shallow’ and ‘deep’ change that could move it toward sustainability. Ultimately, strengthening the HFVC to enhance sustainability depends on the ability to co-create a sustainable, resilient system. Through intentional collaboration,advocacy for hemp fibre, and strategic leadership, the HFVC has the potential to overcome the difficulty of responding urgently to the sustainability challenge while also meeting the time-intensive developmental needs of the system.

Les origines de la variabilité des propriétés du matériau béton de chanvre sont nombreuses. On distingue celles liées aux propriétés des ses constituants et du matériau lui-même auxquelles il faut ajouter les dispersions qui résultent des méthodes utilisées pour caractériser ce béton. Ce travail de thèse, s’intéresse à l’étude de la variabilité des propriétés du béton de chanvre en tenant compte de ces différentes sources et en particulier au type de chènevotte utilisée. L’étude bibliographique réalisée permet de comprendre le matériau béton de chanvre, notamment ses constituants, les méthodes de caractérisations en usage ainsi que l’ampleur de la variabilité et de la sensibilité de ses propriétés vis-à-vis des différents paramètres. Cet état de l’art, permet en outre d’identifier les paramètres à considérer dans le cadre de cette thèse. Notre travail de thèse est alors subdivisé en 4 chapitres en plus de l’étude bibliographique. Dans le deuxième chapitre, une étude multicritère sur les propriétés des chènevottes est présentée. Après une campagne expérimentale de caractérisation de 13 types de chanvre, une analyse des résultats à deux niveaux est réalisée. Elle prend en compte, la masse volumique, la capacité d’absorption d’eau et la granulométrie. Dans un premier temps on présente les résultats de l’étude mono-caractéristique ; il s’agit de la comparaison d’une caractéristique donnée pour l’ensemble des chènevottes. Dans un second temps, on présente les résultats de l’étude multicritère. Il s’agit d’analyser l’ensemble des chènevottes en prenant en comptes les différentes caractéristiques à la fois. A l’issue, les chènevottes sont classées en trois groupes. Le chapitre 3 constitue une étude préliminaire tenant compte des différents paramètres sources de variabilités des propriétés du béton de chanvre, comme le laboratoire d’essai (équipements), la gâchée, la taille d’éprouvette et le type de chanvre. Les résultats obtenus montrent la nécessité d’étudier l’impact du type de la chènevotte. Par ailleurs, la dispersion considérable obtenue pour les résultats du module d’Young est vraisemblablement associée à sa méthode de calcul. Il devient alors important d’approfondir l’étude de son impact sur les valeurs du module d’Young obtenues. Le chapitre 4 vise justement à étudier les méthodes de calcul du module d’Young. Les différentes méthodes de la littérature sont alors utilisées pour exploiter les courbes contrainte-déformation dont les essais ont été réalisés dans les mêmes conditions. Les variabilités observées sur les résultats vis-à-vis de chacune des méthodes permettent alors de mettre en évidence leur impact et de proposer la méthode « flottante » comme étant la plus pertinente. Par ailleurs, un modèle permettant de décrire la loi de comportement mécanique du béton de chanvre est proposé. Il permet de déterminer la courbe enveloppe correspondant à la courbe expérimentale issue du chargement monotone, et permet également de reproduire la courbe expérimentale issue d’un chargement cyclique. Dans le dernier chapitre, en se basant sur les résultats du chapitre 2, neuf types de chanvre ont été sélectionnés pour la confection des éprouvettes de l’étude. Dans les mêmes conditions (fabrication et essai), il a été mis en évidence expérimentalement l’impact de la chènevotte sur les propriétés mécaniques avec un facteur égal à 10 entre les valeurs faibles et élevées. La réponse mécanique caractérisée par des faibles (<5%), moyennes (>5% et <8%) et fortes (>8% et <20%) niveau de déformation a été mis en évidence. Ces variabilités, restent cependant moins marquées pour la conductivité thermique et la masse volumique du béton de chanvre. L’étude met en évidence l’intérêt d’une étude approfondie sur l’interaction liant/chènevotte pour une meilleure compréhension de l’impact de la chènevotte sur le béton de chanvre. / The origins of the variability of hemp concrete material properties are numerous. They include among others those related to the properties of its constituents and material itself as well as the methods used for their characterizations. This thesis is interested in the study of the variability of hemp concrete properties taking into account these different parameters and in particular the type of hemp particles used. The litterature review corried out allowed to present the hemp concrete material, the properties of its constituents, their methods of characterization and also the extend of properties variability and sensitivity due to various parameters. Furthermore, it allowed to identify the parameters to be considered in the context of this thesis. Therefore, this thesis is devided into four chapters in addition to the literature review. In the second chapter, a multi-criteria study on the properties of hemp particles is presented. After an experimental study of characterization for 13 types of hemp particles, a two level analysis of result is performed. It takes into account the density, water absorption capacity and particle size distributions. First, the results of the single characteristic study are presented; it is about a comparison of a given characterstic for all hemp particles at the same time. Secondly, the results of the multi-criteria study are presented. In this last case, the analysis is corried out by taking into account all hemp particles and characteristics, both at the same time. The outcome of this study allowed to classify hemp particles into three groups from which, low, medium and high mechanical peformances are expected, respectively. Chapter 3 is a preliminary study taking into account various parameters as sources of variability for hemp concrete properties, such as the testing laboratory (equipments), the batch, the specimen size and hemp particles type. The obtained results highlight the need for further investigations about the impact of hemp particles type. Moreover, the considerable dispersion in the results of Young’s modulus is likely associated with its calculation method. It then becomes important to deepen the study of its impact on the values of Young’s modulus obtained. The chapter 4 aims to answer the problem found on the method for calculating the Young’s modulus. Various methods from literature are used to analyse the stress-strain curves from samples manufactured under the same conditions. The variability observed in results with respect to used method allowed to highlight their impact and to provide the floating method as the most pertinent since it presents less variability. In addition, a model to describe the mechanical behavior law of hemp concrete is proposed. It allows to determine the enveloppe curve which corresponds to experimental curve from the monotonic loading. It can also allow to reproduce the experimental curve from a cyclic loading. In the last chapter, based on the results of chapter 2, nine types of hemp particles were selected for the preparation and manufacturing of specimens of the study. Under the same conditions (manufacturing and test), it has been demonstrated experimentally the impact of hemp particles on mechanical properties with a factor 10 between low and high values from obtained results. The mechanical response characterized by low (<5%), medium (>5% and <8%) and high (> 8% and <20%) level of deformation have been highlighted. These variabilities remain, however less marked for thermal conductivity and density of hemp concrete material. This study highlights the interest of a comprehensive study on the interaction binder/hemp particles for a better understanding of the impact of hemp particles on hemp concrete.

Tyrimo tikslas – įvertinti skirtingo natūralaus pluošto įtaką kompozicinės medžiagos polietilenas – pluoštas“ mechaninėms savybėms. Bandinių gamyba bei medžiagų mechaninių savybių tyrimai atlikti 2013/2014 m. Aleksandro Stulginskio universitete, Jėgos ir transporto mašinų inžinerijos instituto ir Žemės ūkio inžinerijos ir saugos instituto laboratorijose. Tyrinėjami kompozitai armuoti trimis skirtingai natūraliais pluoštais: kanapių, dilgėlių ir linų. Polietileno klijų kompozitas armuojamas keturiais kiekiais pluošto: 5 %,7 %, 10 % ir12 %. Tempimo ir lenkimo bandymai atlikti „Instron“ medžiagų savybių tyrimo stendu, nustatyta apkrova, kurią atlaiko bandinys ir deformacija. Atlikus lenkimo ir tempimo tyrimus nustatyta, kad geriausia armuojanti medžiaga yra kanapių pluoštas. Tempiant atlaikė didžiausią apkrovą – 753,7 N ir deformavosi 4 mm. Lenkiant kanapių pluoštu armuotas bandinys atlaikė 24,3 N apkrovą ir deformavosi 11,6 mm. / The aim - to evaluate the influence of different natural fiber composite polyethylene - fibers' mechanical properties. Specimen fabrication and mechanical properties of the materials were tested in 2013/2014 year. Alexander Stulginskio University, Power and Transport Machine Engineering and the Institute of Agricultural Engineering and Safety Institute laboratories. Reinforced composites are studied in three different natural fibers: hemp, ramie and flax. Polyethylene adhesive composite reinforced with four volumes of fiber: 5%, 7%, 10%, and 12%. Tensile and flexural tests were examined by using "Instron" material properties testing machine down load the sample and can withstand deformation. After bending and tensile tests showed that the best reinforcement material is hemp. Tensile withstood the maximum load - 753.7 N and deformed 4 mm. bending of hemp fiber reinforced sample withstood 24.3 N load and 11.6 mm.

Ce travail de thèse, s'inscrit dans un accord co-tutelle entre l’École Polytechnique de Thiès du Sénégal, et de l'Université de Franche-Comté. Il a été réalisé au Département de Mécanique Appliquée de l'institut FEMO-ST à Besançon (France). [...]L'objectif de cette thèse est de contribuer à la caractérisation du comportement thermo-hygro-mécaniques des fibres libériennes élémentaires issues du chanvre. Les fibres élémentaires testées dans ce travail ont des diamètres extérieurs moyens d'environ 20µm et des longueurs utiles de l'ordre de 10mm. Des essais couplant des chargements mécaniques, hygroscopiques et thermiques sont réalisés afin d'apporter des éléments de compréhension sur le comportement des fibres et de collecter une base de données sur leurs performances mécaniques.Trois types de comportement sont identifiés sur les fibres en traction quasi statique en fluage pour les différents niveaux hygro-thermique testés. Une rigidification de la fibre est révélée sous chargements cycliques progressifs dans des conditions environnementales constantes. Une chute du module d' Young initial de la fibre est remarquée quand l'humidité relative augmente. Une accélération de la vitesse de déformation différée de la fibre est obtenue en fluage lorsque des cycles d'humidité relative sont appliqués. Une baisse des propriétés mécaniques des fibres sous l'effet de la température est également observée. Elle dépend directement du niveau de la durée de l'exposition à la température. / The thesis work joins in the framework in joint supervision between the Polytechnic school in Thies (Sénégal) and the University of Franche-Comté (France)[...]The aim of this thesis is to contribute to the characterization of thermo-hygro-mechanical behaviour of elementary hemp fibres. These fibres used in this work have an average diameter approximately 20µm and useful length of only 10 mm. The méchanical, hygroscopic and thermal coupling testing are realized to provide some understanding of the behaviour of the hemp fibres and to collect details from a database on their mechanical performance.From the uniaxial quasi static tensile tests and creep tests, three categories of behaviours are measured and observed. How ever subject to constant environmental conditions, a fibre hardening is observed under cyclic tensile loading. It was also found that a drop of the initial Young 's modulus of the hemp fibres when the relative humidity gradually increases. Thus, the strain rates measured on the fibres during creep exhibited a speeding up relative humidity cycles are imposed . We found also that the mechanical properties of the fibres decrease under temperature effects. It depends directly on the level and exposure time to temperature