Les lichens sont des organismes symbiotiques constitués d'un champignon (mycobionte) associé à une algue et/ou une cyanobactérie (photobionte). Leurs métabolites secondaires sont des molécules originales appartenant au groupe des depsides, depsidones, dibenzofuranes et présentent un intérêt pour la cosmétique et/ou la pharmaceutique en raison de leur propriété antibiotique, anti-inflammatoire, antioxydant, filtre UV. Nous avons choisi d'étudier le lichen Pseudevenia furfuracea qui est l'un des lichens utilisés en tant que matière première pour la parfumerie et la cosmétique (1900 tonnes / an), car il est d'une part abondant dans la nature et d'autre part, il possède des métabolites secondaires très variés. Classiquement, les extraits utilisés sont obtenus par extraction au reflux de solvants organiques; cette méthode à l'inconvénient d'induire des durées d'extractions relativement longues et est consommatrice en solvants. L'objectif de notre travail est d'extraire les métabolites secondaires d'une manière sélective et innovante tout en diminuant la durée d'extraction. Pour cela, nos travaux reposent sur l'extraction assistée sous micro-onde (EAM) combinée ou non aux liquides ioniques. Dans ce dessein, deux familles de liquides ioniques (LIs) "hydrophiles" et "hydrophobes" ayant un cation imidazolium et pyridinium ont été synthétisés. Trois différentes préparations de lichen (mixé, broyé au mortier et broyé planétaire) ont été effectuées en faisant varier la granulométrie et chaque préparation a été étudiée par microscopie électronique à balayage. L'optimisation de l'EAM a été effectuée à une température d'extraction optimale de 75 °C et a permis de générer un énorme gain de temps (24 h sous conditions classiques contre 15 min sous irradiation micro-onde). Une étude comparative des taux d'extraction entre l'EAM et l'extraction en condition classique a été éffectuée par analyse au spectrodensitomètre CAMAG®, celle-ci a montré que la première est plus performante dans la plupart des cas. L'utilisation des liquides ioniques a mis en évidence l'existence d'une sélectivité d'extraction en fonction de la structure des LIs qui résulte d'interactions intermoléculaires entre les LIs et les substances extraites. L'effet de chaque liquide ionique sur la dégradation d'un des métabolites, en particulier l'atranorine, a également été étudié. Également, les interactions entre un liquide ionique et la surface du lichen ont été étudiées par mesure d'angle de contact et par les mesures de Brunauer Emett et Teller. Une extraction à plus grande échelle a été réalisée pour étudier la reproductibilité de la méthode et la possibilité de recycler le liquide ionique. / Lichens are symbiotic organisms constituted of fungus (mycobiont) associated to algae and/or cyanobacteria (photobiont). Their secondary metabolites are original molecules belonging to the group of depsides, depsidones, dibenzofurans. Lichens presented special interest for cosmetic and pharmaceutical industry due to their antibiotic, anti-inflammatory, antioxidant and UV filter properties. In this work we focused our study on Pseudevenia furfuracea lichen, which is intensively used as a raw material in perfumery and cosmetics (1900 tons/year), due to its large availability in nature as well as possessing various secondary metabolites. In this work we presented extraction of the secondary metabolites using a selective and innovative solventfree method in shorter extraction time in comparison to the conventional extraction methods requiring under reflux of large quantities of solvents with longer times for extraction. The proposed method is based on the use of microwave irradiation for extraction (MIE) associated to (or not) appropriate ionic liquids. Two kinds of hydrophilic or hydrophobic imidazolium- and pyridinium-based ionic liquids (ILs) were synthesized. Three different methods of grinding for lichen were used, leading to different particle size and the crushed products were observed by scanning electron microscopy (SEM). Heating optimization of MIE was performed during 15 min at optimal temperature (75 °C) (instead of 24 h under conventional heating). A comparative study of extraction rates between MIE and extraction with conventional heating was realized with a CAMAG® spectrodensitometer and results of analysis showed that MIE is efficient in most of the studied cases. The use of ionic liquids showed selectivity for extraction and it depended on the structure of ILs and also intermolecular interactions between ILs and extracted substances.Effect of each ionic liquid on the degradation of one of the secondary metabolites, atranorin, was also been studied. In addition, interactions between IL and the surface of the lichen surface were studied by measurements of the angle of contact and by Brunauer Emett and Teller measurements. Scale-up for extraction was carried out to investigate the reproducibility of the method and the possibility of reuse of the ionic liquid.

This thesis deals with digital image stabilization. It contains a brief overview of the problem and available methods for digital image stabilization. The aim was to design and implement image stabilization system in JAVA, which is designed for RapidMiner. Two new stabilization methods have been proposed. The first is based on the motion estimation and motion compensation using Full-search and Three-step search algorithms. The basis of the second method is the detection of object boundaries. The functionality of the proposed method was tested on video sequences with contain visible shake of the scene, which has beed created for this purpose. Testing results show that with the proper set of input parameters for the object border detection method, successful stabilization of the scene is achieved. The rate of error reduction between images is approximately about 65 to 85%. The output of the method is stabilized image sequence and a set of metadata collected during stabilization, which can be further processed in an environment of RapidMiner.

This study investigates which English variety teachers in Sweden learned, which they use now and whether this has changed over time. The study included the two major varieties of English, namely British English and American English.  The hypothesis for this paper is that British English will have played an important part in the teachers’ schooling but American English will have had a strong influence in their day-to-day lives and will likely have hanged how they use English. Data was collected in the form of questionnaires filled in by 294 teachers who teach English at primary, secondary and upper secondary schools in Sweden.  The results support the thesis of the paper that teachers mainly learned British English at school while American English becomes more common for teachers under the age of 40. However, the majority of participants were found to use a variety which has features of both British and American English - it is referred to as Mid-Atlantic English in this paper.

English is today a vast world language, and the foremost important business and cross-border language in the world. The two predominant English varieties in the Swedish educational system are British English and American English. A third variety, Mid-Atlantic English, is however on the up-rise, and many researchers expect this to be the future educational standard variety due to escalating globalization. British English is the variety which traditionally has been taught in the Swedish school, but the last couple of decades American English have been gaining ground because of popular media. Today both varieties are referred to in the Swedish National Curriculum, and teachers as well as students face a multifaceted choice. The aim of this paper is to investigate attitudes among upper-secondary level teachers and students; on what grounds they have chosen their personal variety and to what extent they are aware of what English variety they use. What we have seen is that resolute attitudes can be perceived towards the two Englishes. Furthermore, our investigation shows that students mix British and American English, and even though British English still is held in academic esteem, American English characteristics predominate in the mix. British English is recurrently described as “snobbish” and in a more positive fashion as “high-class”, whereas American English is perceived either as “youthful and cool” or “dim and uneducated”. Even students who prefer and think they use British English, to a large extent use American orthography and spelling.

Denna studie har undersökt hur kommuner i Stockholms län följer upp det systematiska kvalitetsarbetet vid de privata skolföretag som kommunen har avtal med för att erbjuda kommunal vuxenutbildning till sina kommuninvånare. Studien önskade att samla in en så heltäckande bild som möjligt gällande vilka arbetssätt som användes i denna uppföljning samt undersöka på vilket sätt uppföljningen kan bidra till ett förbättringsarbete. Datainsamlingsmetoden som valdes var enkäter, dessa skickades till rektorer på kommunerna och till rektorer på privata skolföretag. Enkäten som var riktad mot kommuner skickades ut till 22 rektorer som tillsammans representerade Stockholms läns 26 kommuner. Enkäten som var riktad mot skolor skickades ut till 39 rektorer som representerar de 39 privata skolföretag som har avtal med en eller flera av Stockholms läns kommuner. Svarsfrekvensen för respondenter från kommun blev 46,1% och respondenter från skola blev 28,2%. Den totala svarsfrekvensen landade på 35,3%.  Resultatet visade att de arbetssätt som användes var bland annat: ·         Kontinuerlig kontakt med skolorna under terminen ·         Fysiska besök på skolorna ·         Samla in elevers synpunkter ·         Läsa skolornas årsrapporter ·         Begära in olika typer av dokumentation ·         Begära in handlingsplaner när brister upptäcks ·         Skapande av forum för dialog och erfarenhetsbyte Resultatet visade att sätt där uppföljningen kunde leda till utvecklig var bland annat att: ·         Brister upptäcks ·         Uppföljningen underlättar dialog och vidare samarbete ·         Stöd gällande lag och förordning ·         Goda exempel kunde lyftas Resultat och analys visade dock att det fanns en viss diskrepans mellan svaren hos kommunrepresentanter och skolrepresentanter. Kommunrepresentanterna ansåg i högre utsträckning att uppföljningen var utformad i syfte att utveckla utbildningen tillsammans med skolan, att den dokumentation som begärdes in användes i ett utvecklingsarbete samt att arbetet har ett fokus på både kvalitetssäkring och kvalitetsutveckling medan skolrepresentanterna inte upplevde detsamma i lika stor utsträckning. / This study has examined how municipalities in Stockholm County follow up the systematic quality work at the private school companies with which the municipality has an agreement to offer municipal adult education for its municipal residents.  The data collection method chosen was questionnaires sent to principals in the municipalities and to principals of private school companies. The questionnaire, which was aimed at municipalities, was sent to 22 principals who together represented all the municipalities in Stockholm County. The questionnaire, which was aimed at schools, was sent out to 39 principals representing private school companies that have agreements with one or more municipalities in Stockholm. The response rate for respondents from the municipalities was 46,1% and respondents from school was 28,2%. The total response rate ended up at 35,3%.  The results showed that the methods used by the municipalities included: ·         continuous contact with the schools during the semester  ·         physical visits to the schools ·         collecting student views ·         reading annual reports ·         requesting different types of documentation ·         requesting action plans when deficiencies are discovered ·         creation of forums for dialogue and exchange of experience The results showed ways in which the follow-up could lead to development:  ·         discovering deficiencies ·         the follow-up facilitates dialogue and further cooperation ·         support for current law and regulations ·         good examples could be highlighted.  The results and the analysis showed, however, that there was a certain discrepancy between the answers of municipal representatives and school representatives. The municipal representatives considered to a greater extent that the follow-up was designed with the aim of improving the education together with the school, that the documentation requested was used in a development work and that the follow-up has a focus on both quality assurance and quality improvement while the school representatives did not fully experienced it in the same way. / <p>2022-06-05</p>

M. Tech. (Department of Information Communication Technology, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Too many options on the internet are the reason for the information overload problem to obtain relevant information. A recommender system is a technique that filters information from large sets of data and recommends the most relevant ones based on people‟s preferences. Collaborative and content-based techniques are the core techniques used to implement a recommender system. A combined use of both collaborative and content-based techniques called hybrid techniques provide relatively good recommendations by avoiding common problems arising from each technique. In this research, a proactive University Library Book Recommender System has been proposed in which hybrid filtering is used for enhanced and more accurate recommendations. The prototype designed was able to recommend the highest ten books for each user. We evaluated the accuracy of the results using Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE). A measure value of 0.84904 MAE and 0.9579 RMSE found by our system shows that the combined use of both techniques gives an improved prediction accuracy for the University Library Book Recommender System.

Chromatography and extraction techniques, and also chemiluminescence have been utilized to develop new rapid and informative tools in the evaluation of long-term properties and environmental effects of polymeric materials. Methods were developed for classification of materials and for early and rapid degradation detection. Degradable polyethylene films were classified on the basis of their incorporated prooxidant systems using chromatographic fingerprinting of carboxylic acids, the dominating type of degradation product. The fingerprints were also shown to be useful for prediction of the degradation states and evaluation of the degradation mechanisms. Classification and prediction models were obtained by Multivariate Data Analysis, where the diacids were grouped according to both their type of prooxidant system and their state of degradation. The use of total luminescence intensity (TLI) measurements was also investigated as a means of classifying films and for the early detection of degradation. Comparisons were carried out with common techniques, e.g. FTIR and DSC, after both thermal and UV oxidation. TLI gave an earlier detection of degradation and was more sensitive than carbonyl index and crystallinity measurements to relative differences in degradation between the materials. It furthermore offered complementary information regarding changes in activation energies during the course of the degradation. The results were compared with the chromatographic fingerprints. A new way to evaluate the low temperature long-term stabilisation efficiency of antioxidants was investigated. A prooxidant was used to obtain catalytic oxidation, instead of using thermal acceleration, to evaluate the stabilisation efficiency of antioxidants at low temperatures but still during reasonably short aging times. Comparisons were made between polypropylene films stabilised with primary antioxidants (Irganox 1076, Irganox 1010 and α-tocopherol) with and without the prooxidant manganese stearate at different temperatures. The relative efficiencies of the antioxidants obtained under prooxidant acceleration test correlated better than thermal acceleration test with the results of a long-term low temperature test. Additives in plastic packaging materials may affect the environment after migration from the packaging to e.g. their contents, especially if they consist of organic aqueous solutions or oils. The use of Solid-Phase Microextraction (SPME) for the specific task of extraction from an organic aqueous solution such as a simulated food or pharmaceutical solution consisting of 10 vol-% ethanol in water was investigated. Methods were developed and evaluated for extraction both with direct sampling and with headspace sampling. If the extraction method and temperature were selected to suit the concentration levels of the analytes, it was possible to quantify several degradation products simultaneously. Comparisons made with Solid Phase Extraction showed the advantage of SPME for this purpose. / QC 20100929

L'arsenic est un élément présent dans tous les compartiments de l'environnement, et les produits de la pêche représentent une source majeure d'exposition à l'arsenic par le biais de l'alimentation. Même s'il n'existe pas à ce jour de législation sur les teneurs en arsenic dans les aliments en France, les agences gouvernementales évaluent généralement les risques liés à la présence d'arsenic dans les produits de la pêche en se basant essentiellement sur la concentration totale de l'élément, sans tenir compte des différentes espèces présentes ni de leur bioaccessibilité. Par conséquent, le développement de méthodes d'analyse de spéciation revêt un intérêt particulier dans le cadre de l'évaluation des risques. La première partie de ce mémoire présente des informations générales sur les propriétés de l'arsenic, son occurrence dans les différents compartiments de l'environnement et sa toxicité, ainsi qu'une étude bibliographique des méthodes analytiques existantes pour étudier la spéciation de l'arsenic dans les matrices alimentaires, en particulier les produits de la pêche (extraction et séparation/détection). Les différentes approches pour l'évaluation de sa bioaccessibilité et de celle d'autres éléments traces métalliques d'intérêt sont également présentées. La deuxième partie de ces travaux porte sur la validation d'une méthode d'analyse de spéciation des principales espèces d'arsenic dans les produits la pêche (As(III), MA,DMA, As(V), AsB, TMAO, AsC) par couplage entre la chromatographie d'échange d'ions (IEC) et la spectrométrie de masse à plasma induit (ICP-MS) après extraction assistée par micro-ondes (MAE). L'évaluation des performances analytiques de la méthode, les contrôles qualités internes et externes mis en place et les différentes applications, en particulier les données d'occurrence des différentes espèces d'arsenic dans les produits de la pêche les plus consommés par la population française sont présentés et discutés. Dans la troisième partie, la bioaccessibilité maximale de l'arsenic et d'autres éléments d'intérêt est estimée à l'aide d'une méthode de lixiviation en ligne (impliquant la mesure en temps réel par ICP-MS de la fraction libérée par les différents fluides digestifs artificiels). La combinaison de ce procédé avec la méthode d'analyse de spéciation validée permet ainsi d'estimer la bioaccessibilité des différentes espèces d'arsenic.