Flax is one of the major cash crops in Canada. Approximately seventy percent of Canadian flaxseed was exported to European Union (EU) annually until 2009. In 2009, the EU imposed an import ban on Canadian flaxseed due to the adventitious presence of a GM flax variety - CDC Triffid was identified in Canadian flaxseed exported to the EU. The EUs decision to apply zero tolerance on CDC Triffid flax has been based on its interpretation of the precautionary principle. According to the World Trade Organisations Agreement on the Application of Sanitary and Phytosanitary Measures (SPS), however, precautionary measures are subject to a scientific risk assessment. As the EU did not base its zero tolerance for CDC Triffid flax on any scientific risk assessment, the EU is in violation of the SPS Agreement. Moreover, the EU has ignored the available scientific information regarding CDC Triffid flax. The EU did not consider the possibility of following the guidelines given by Codex Alimentarius Commission in the case of CDC Triffid flax. There are non-scientific reasons behind the EUs zero tolerance on CDC Triffid flax and they overweigh the available scientific information. The EU position would be unlikely to be supported if a complaint was brought to the World Trade Organisation Disputes Panel. A partial equilibrium model was used to provide a theoretical background to examine the changes in the flaxseed industry and the linseed oil industry due to the CDC Triffid event. A model of the supply chain of Canadian flaxseed was developed to illustrate the operationalisation of the Protocol developed by the EU and Canada to address the zero tolerance policy. Empirical estimation suggests that the operationalisation of the Protocol incurred additional cost of $7.5 million to the flax seed industry of Canada in 2009/ 2010. Out of that, cost of testing was approximately $1.2 million and cost of segregation was $4.2 million. Estimation of changes in revenue suggests that there was a loss of revenue in flaxseed trade between the EU and Canada in 2009/2010. Imports of Canadian flax by China provided an alternative market, at a considerably lower price than typically realised from the EU market. Interestingly, the EUs zero tolerance policy on CDC Triffid flax has resulted in a larger additional cost on the EU than Canada.

Magistriniame darbe, naudojant mokslinės literatūros, aprašomąjį analitinį, teisės aktų ir dokumentų analizės metodus bei pusiau struktūruotą interviu, analizuojamas ES bendrosios žemės ūkio politikos įgyvendinimas linininkystės sektoriuje pasirenkant ir ištiriant konkretų probleminį Lietuvos atvejį. Siekiant atsakyti į išsikeltus uždavinius, pirmojoje darbo dalyje ES bendroji žemės ūkio politika bei Lietuvos prisijungimas prie jos aiškinami tarpvyriausybiškumo teorijos kontekste, aptariant sąlygiškumo nuostatą ir panagrinėjant ES interesų grupių įtaką sprendimų priėmimui. Antrojoje darbo dalyje analizuojami svarbiausi ES bendrosios linų rinkos teisiniai dokumentai, išskiriami buvę ir esami paramos šiam sektoriui modeliai, nagrinėjama kaip linininkystė reguliuota ir subsidijuota Lietuvoje nepriklausomybės laikotarpiu iki prisijungiant prie ES ir po 2004 m. Trečiasis darbo skyrius skirtas Lietuvos linininkystės sektoriaus vystymosi, administravimo ir finansavimo aptarimui. Išsiaiškinta, jog linų ūkio sektoriaus regreso tendencijos Lietuvoje pastebėtos dar prieš prisijungimą prie ES. Ketvirtajame svarbiausiame šio darbo skyriuje, atlikus pusiau struktūrinį interviu, pasitelkus Lietuvos linų sektoriaus atstovų ir ekspertų nuomones, nusakomos giluminės linininkystės krizės priežastys analizuojant, kodėl šio sektoriaus prisijungimas prie ES bendrosios žemės ūkio politikos sukėlė negatyvius padarinius. Identifikuojama, jog Lietuvos linininkystės sektoriaus krizinė situacija... [toliau žr. visą tekstą] / The master thesis, using the scientific literature, descriptive analytical and document analysis methods as well as semi-structural interview, analyses the implementation of the common agriculture policy of the EU in the sector of flax culture choosing a particular case in Lithuania. Seeking to fulfill the set tasks, the first part of the theoretical part of the thesis, the common agriculture policy of the EU as well as the joining of Lithuania to it are explained in the intergovernmental theory context, discussing the provisions of conditionality and analyzing the influence of the EU interest groups upon the decision making. The second part of the thesis analyses the most important legal documents of the common linen market of the EU, the former and present models of the support for this sector are distinguished, the analysis is provided on how the flax culture was regulated and subsidized during the period of independence of Lithuania till the accession to the EU and after the year of 2004. The third sector of the thesis is devoted to the discussion of the development, administration and financing of the flax culture sector of Lithuania. The conclusion was made that the tendencies of the regress of the flax culture sector were distinguished before the accession to the EU. The fourth sector, with the help of the opinions of the representatives and experts of the flax sector of Lithuania, the deeper reasons of the linen market crisis of Lithuania are outlined, after... [to full text]

Magistrantūros studijų baigiamajame darbe pateikiami veiksnių, lemiančių pluoštinių linų morfogenezę in vitro, tyrimų duomenys. Darbo objektas – keturios pluoštinių linų veislės 'Dangiai', 'Sartai', 'Snaigiai' ir 'Vaižgantas'. Darbo metodai. Pluoštinių linų morfogenezei somatinių audinių kultūroje tirti naudoti hipokotilio eksplantai. Eksplantai auginti MS terpėje su skirtingais augimo reguliatorių kiekiais auginimo kambaryje. Vertintas pridėtinių pumpurų formavimosi dažnis (%) ir pridėtinių ūglių kiekis iš eksplanto (vnt.). Darbo rezultatai. Egzogeninių augimo reguliatorių priedas indukcijos terpėje daugeliu atvejų skatino tirtų pluoštinių linų veislių ūglių regeneraciją, tačiau optimali šio junginio koncentracija priklausė nuo genotipo. Iš tirtų pluoštinių linų veislių didžiausia morfogenine galia pasižymėjo veislės 'Vaižgantas' izoliuoti hipokotiliai. Priklausomai nuo genotipo ir maitinamosios terpės sudėties pluoštinių linų pridėtinių pumpurų formavimosi procesas hipokotilių kultūroje vyko 2,87-94,50 % dažniu regeneruojant 1,67-6,00 ūglius iš eksplanto. Efektyviam veislės 'Dangiai' ūglių regeneravimui maitinamąją terpę tikslinga papildyti 2,0 mg l-1 BAP + 0,1 mg l-1 NAR bei eksplantus paveikti 4 °C temperatūra 24 valandas. Veislės 'Sartai' izoliuotų hipokotilių audinių antrinę diferenciaciją skatino 72 valandų 7 °C temperatūros poveikis bei citokinino 1,0 mg l-1 2iP priedas maitinamojoje terpėje. Intensyviausiai veislės 'Snaigiai' eksplantai pumpurus formavo maitinamojoje... [toliau žr. visą tekstą] / The master work presents the results of fibre flax morphogenesis in vitro affecting factors. Object of the research − four fibre flax cultivars 'Dangiai', 'Sartai', 'Snaigiai' and 'Vaižgantas'. Research methods. To study fiber flax morphogenesis of somatic tissues hypocotyls were used as explant. Explants were placed on MS medium supplemented with different combinations of growth regulators and cultivated in growth chamber. The percentage of bud regeneration and the number of shoots per explant were evaluated. Research results. Exogenous growth regulators concentration in induction media increased fiber flax shoots regeneration, and therefore specific combination of growth regulators must be designed for each genotype. Among investigated genotypes, the hypocotyls of cultivars 'Vaižgantas' manifested the best morphogenic capability. Depending on genotype and medium composition fiber flax adventitious buds regeneration frequency varied from 2.87-94.50% and the number of shoots per explant reached 1.67-6.0, respectively. Hypocotyls of cultivar 'Dangiai' showed the best response on medium supplemented by 2.0 mg l-1 BAP with 0.1 mg l-1 NAA and pretreated by 4 °C temperature 24 hours. In the presence of only cytokinins, the highest mean value of regenerated shoots was observed on medium supplemented with 1.0 mg l-1 2iP and 72 hours 7 °C temperature pretreatment for hypocotyls of 'Sartai'. Growth regulators combination 2.0 mg l-1 2iP with 0.1 mg l-1 NAA and treatment by 4 °C... [to full text]

Omega-3 enriched eggs serve as an important functional food to boost consumption of polyunsaturated fatty acids (PUFA) critical for good health. Because omega-3 eggs have the potential for unpleasant aromas and flavours, this research was designed to assess the fatty acid profile and sensory attributes of eggs procured from hens consuming designer diets. In the first study, the use of hemp in hen diets led to significant increases in omega-3 PUFA content and colour intensity of yolks, but did not have adverse effects on the sensory profiles of cooked eggs. Additionally, the level of docosahexaenoic acid was the same in eggs from both the lowest and highest hempseed oil groups. In order to overcome this plateau, the second study assessed diets varying in linoleic acid (LA) content. Although docosapentaenoic acid in the yolk was significantly increased with an increasing dietary LA content, docosahexaenoic acid remained unaffected by dietary treatment. In the third study, a different approach was used to reduce competition between alpha-linolenic acid (ALA) and LA. Diets containing two levels of ALA and varying ratios of saturated fatty acids (SFA): LA + oleic acid (OA) were tested. Increasing dietary SFA: LA + OA resulted in marked increases in all n-3 PUFA. The fourth study was designed to assess the interaction between dietary constituents on sensory attributes of eggs, namely omega-3 PUFA from flaxseed oil (FO), and canola meal (CM), which contains precursors to trimethylamine, which may lead to fishy taint. Oceanic flavour significantly increased with inclusion of FO, while egg, creamy and buttery flavours showed a decrease. The pairing of CM and FO resulted in a significant decrease in egg flavour compared to using FO alone. This research has demonstrated that novel ingredients like hemp can be used in laying hen diets to deposit n-3 PUFA into eggs without fear of affecting sensory outcomes. Increasing the SFA: LA + OA ratio in layer diets is most effective in increasing yolk ALA conversion into long-chain PUFA. Lastly, CM should be added to diets with caution when used in conjunction with omega-3 PUFA ingredients due to a reduction in egg flavour.

The goal of the project was to enhance the period of weed growth prior to seeding in order to reduce weed emergence and weed competition after the crop has been planted. Weed growth was stimulated using either light tillage or by applying nitrogen fertilizer early in the spring. Light disturbance significantly increased pre-seed weed emergence while early applied nitrogen did not appear to have an effect. Post seeding weed emergence levels and weed biomass were similar among the light tillage and early nitrogen treatments. Therefore the goal of decreasing weed competition after seeding was not attained. Future research should focus on long-term strategies to reduce weed populations in field rather than seasonal strategies.

Thermoplastic composites using natural fibres are studied intensively and widely used in applications including automotive, packaging, consumer goods and construction. Good balance of mechanical properties, processability and low cost are great advantages of these materials on top of the environmental benefits. Recently, there have been various efforts to amplify the positive effects on the environment by replacing the conventional polymers by bio-derived renewable polymers in the composites. Recent studies conducted from our research group showed competitiveness of plant fibre-thermoplastic composites. Implementing the promising results and experience, a new composite design using renewable polyethylene as the matrix material was studied. This polyethylene is a renewable thermoplastic that was derived from sugar cane ethanol. The objectives of this study were to employ renewable high density polyethylene (HDPE) into composites using wheat straw and flax fibre to extend the range of properties of the HDPE while keeping the amount of renewable content to nearly 100%. The chemical resistance of these materials has not been reported before and it was investigated here by measuring and comparing the properties before and after accelerated chemical ageing. Both wheat straw and flax fibre had two different grades in size. Each of them was compounded with HDPE and additives (antioxidant and coupling agent) in a co-rotating twin screw extruder. The concentrations of fibres were varied from 0 to 30 wt-%. Then, injection molded samples were prepared for measurement of properties: tensile, flexural, impact tests. The effects of reinforcing fibre size were studied first. Both length and aspect ratio were considered. For both types of fibre composites, a general trend was observed. There was no clear evidence of improvements in flexural (strength and modulus) and tensile (strength, percentage elongation at break) properties with respect to the change in fibre size. However, impact (IZOD impact strength, Gardner impact failure energy) properties showed some improvements. This result was due to no substantial difference in size and aspect ratios in post-processed fibres that were actually residing in the matrix. There were remarkable improvements in flexural strength and modulus when the fibre content increased. However, minor decreases in tensile properties were observed. Furthermore, the impact properties were very sensitive to the concentration of fibres. As the fibre concentration went up, there were significant decreases in both IZOD impact strength and Gardner impact failure energy. Chemical resistance of these composites was studied by exposing them in six different chemical solutions (hydrochloric acid, acetic acid, sodium hydroxide, ethyl alcohol, industrial detergent, water) for up to thirty days. The increase in weight and leaching behaviour was observed. As the fibre content increased within the composites, the weight gain was more rapid during chemical ageing. Because there were more fibres exposed on the surface after chemical ageing, it is likely that they contributed to the higher flux of liquids (used for chemical ageing) inside the sample. Among the physical properties, tensile properties were most susceptible to the chemical ageing. One possible reason could be due to the exposed surface area to volume ratio, which was the highest in tensile bars and therefore faster mass transfer taking place into the matrix per volume. Finally, morphological study using scanned electron spectroscopy (SEM) revealed the damage on the surface when exposed to the chemicals. The fibres on the surface had been leached out in the sodium hydroxide solution leaving empty spaces. The fractured surface was also monitored via SEM. Though there was not enough evidence of strong interfacial interactions between the fibre and the polymer, good dispersions were observed.

The goal of the project was to enhance the period of weed growth prior to seeding in order to reduce weed emergence and weed competition after the crop has been planted. Weed growth was stimulated using either light tillage or by applying nitrogen fertilizer early in the spring. Light disturbance significantly increased pre-seed weed emergence while early applied nitrogen did not appear to have an effect. Post seeding weed emergence levels and weed biomass were similar among the light tillage and early nitrogen treatments. Therefore the goal of decreasing weed competition after seeding was not attained. Future research should focus on long-term strategies to reduce weed populations in field rather than seasonal strategies.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Cette thèse s’intéresse au tissage et au préformage de renforts fibreux à base de fibres de lin. Avant d’être utilisés, ces fibres sont disposées en faisceaux de faible longueur (~ 30 mm en moyenne) et ont besoin d’être assemblées pour constituer un renfort linéaire continu. L’utilisation de rubans ou de rovings sans torsion est recommandée pour des applications composites. Dans un premier temps, cette étude se concentre sur l’élaboration et l’utilisation de rovings traités par un agent d’encollage et sans torsion ainsi que sur l’influence des paramètres du procédé de tissage sur les propriétés mécaniques et les caractéristiques textiles des renforts tissés. Pour éviter l’endommagement de ces rovings durant le tissage, des solutions sont proposées. Dans un second temps cette thèse s’intéresse à la mise en forme de ces renforts sur une géométrie complexe. Ce travail se concentre alors sur l’étape de préformage du procédé RTM. Une approche expérimentale est abordée pour identifier et quantifier les défauts apparaissant durant l’emboutissage sur une géométrie complexe comme le tétraèdre. Cette analyse se concentre en particulier sur le défaut de bouclage causé par un fléchissement des mèches. Des solutions comme l’optimisation de l’architecture des renforts sont observées pour obtenir cette géométrie complexe sans défaut avec des renforts à base de fibres de lin. La forme, le positionnement ainsi que la pression appliquée sur les serre-flans maintenant le renfort au cours du passage du poinçon influent également sur la génération des défauts. L’optimisation du procédé d’emboutissage pour empêcher l’apparition de boucles sur les préformes conclut ce travail. / This work focuses on the weaving and forming of flax based reinforcements. Before being woven, naturalfibres on the form of finite length bundles (~ 30 mm in average for flax) need to be assembled together in a1D continuous product. The use of roving or slivers without twist is rather recommended for compositeapplications. In a first part, this study focuses on the manufacturing and the use of untwisted rovings treatedwith a bonding agent as well as on the weaving process parameters that may influence the mechanicalproperties and the textile characteristics of the woven fabric. Solutions to prevent roving defects duringweaving are proposed. In a second part, this study investigates the ability to develop composite parts with complex geometrieswithout defect. It focuses on the first step of RTM process which consists in forming dry fibrousreinforcements. An experimental approach is used to identify and quantify the defects. The buckling defectcaused by the bending of tows during the preforming step is particularly investigated. Solutions to realize acomplex shape such as a tetrahedron without any defect from flax based woven reinforcements areproposed. With optimized reinforcement architecture, buckling can be prevented. Another solutionconsisting in optimising the process parameters such as the blank holder geometry or the blank holderpressure to prevent the appearance of buckles from commercial fabrics was also investigated with success.

Searching for environmentally sustainable alternatives for reinforcement of composite materials, flax fibre has one of the most promising potentials due to its desired mechanical properties. The fact that flax is a bio-material, in contrast to conventional synthetic fibres, does not ensure a less environmental impact. One of the major source of environmental impact related to flax fibre as a reinforcement material is the cultivation of flax fibre. In this study the environmental impact of flax fibre cultivation was studied by performing an environmental impact analysis with a life cycle assessment inspired approach.  The result showed that the quantification of the environmental impacts varied to a large extent depending on several parameters such as allocation method and whether carbon sequestration was included in the calculations. One striking example is the results for global warming potential, ranging from 10 000 kg CO2-equivivalents to a negative value per 1 tonne of flax fibre. The study showed the production and use of fertilizers to be the major contribution to the environmental impact by as much as 70-90 %. In order to limit the environmental impact from flax fibre cultivation suggested environmental improvements are to optimise the fertiliser use according to the flax type and soil conditions, improving nitrogen fixation as well as using organic fertilizers. / <p>2018-06-27</p>