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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

An investigation into the role of forward head posture as an associated factor in the presentation of episodic tension-type and cervicogenic headaches

Duani, Victor January 2010 (has links)
Dissertation submitted in partial compliance with the requirements for a Master's Degree in Technology: Chiropractic, Durban University of Technology, 2010. / Forward head posture (FHP) is a common postural abnormality, often associated with myofascial trigger points which can result in head and neck pain. The craniovertebral (CV) angle lies between a horizontal line running through C7 spinous process and a line connecting C7 spinous process to the tragus of the ear. The smaller the angle the greater the FHP. Cervical musculoskeletal abnormalities have often been linked to headache types, most especially episodic tension-type headache (ETTH) and cervicogenic headaches (CGH). Objectives: To determine whether an association exists between FHP, distance of the external auditory meatus (EAM) from the plumbline and cervical range of motion and the presentation of ETTH and CGH. Method: This was a quantitative comparative study (n=60) comparing three equal groups, one with ETTH, CGH and healthy controls. The FHP of the Subjects FHP was assessed by measuring the CV angle. A lateral digital photograph was taken to assess the distance of the external auditory meatus from the plumbline. Lastly, cervical range of motion was measured. The two symptomatic groups also received a headache diary for a fourteen day period monitoring frequency, intensity and duration of their headaches. Result: The two symptomatic groups had a smaller CV angle and a greater distance from the plumbline (p<0.05) than the asymptomatic group. The asymptomatic group had a significantly greater flexion (p=0.009), extension (p=0.038) and left rotation (p=0.018) range of motion than the two symptomatic groups. The CGH group had a significant positive correlation between the distance of the EAM from the plumbline and the intensity of headaches. The ETTH group had a significant positive correlation between the right craniovertebral angle and the mean duration of headaches. Conclusion: Therefore, it can be concluded that patients presenting with ETTH and/or CGH may have associated postural abnormalities that may act as a trigger or a contributory factor to the presenting headache. / Durban University of Technology
32

An investigation into the role of forward head posture as an associated factor in the presentation of episodic tension-type and cervicogenic headaches

Duani, Victor January 2010 (has links)
Dissertation submitted in partial compliance with the requirements for a Master's Degree in Technology: Chiropractic, Durban University of Technology, 2010. / Forward head posture (FHP) is a common postural abnormality, often associated with myofascial trigger points which can result in head and neck pain. The craniovertebral (CV) angle lies between a horizontal line running through C7 spinous process and a line connecting C7 spinous process to the tragus of the ear. The smaller the angle the greater the FHP. Cervical musculoskeletal abnormalities have often been linked to headache types, most especially episodic tension-type headache (ETTH) and cervicogenic headaches (CGH). Objectives: To determine whether an association exists between FHP, distance of the external auditory meatus (EAM) from the plumbline and cervical range of motion and the presentation of ETTH and CGH. Method: This was a quantitative comparative study (n=60) comparing three equal groups, one with ETTH, CGH and healthy controls. The FHP of the Subjects FHP was assessed by measuring the CV angle. A lateral digital photograph was taken to assess the distance of the external auditory meatus from the plumbline. Lastly, cervical range of motion was measured. The two symptomatic groups also received a headache diary for a fourteen day period monitoring frequency, intensity and duration of their headaches. Result: The two symptomatic groups had a smaller CV angle and a greater distance from the plumbline (p<0.05) than the asymptomatic group. The asymptomatic group had a significantly greater flexion (p=0.009), extension (p=0.038) and left rotation (p=0.018) range of motion than the two symptomatic groups. The CGH group had a significant positive correlation between the distance of the EAM from the plumbline and the intensity of headaches. The ETTH group had a significant positive correlation between the right craniovertebral angle and the mean duration of headaches. Conclusion: Therefore, it can be concluded that patients presenting with ETTH and/or CGH may have associated postural abnormalities that may act as a trigger or a contributory factor to the presenting headache. / Durban University of Technology / M
33

Recalage et fusion d'informations multimodales pour l'optimisation de la thérapie de resynchronisation cardiaque

Tavard, François 24 April 2012 (has links) (PDF)
Ces travaux portent sur le recalage et la fusion d'informations multimodales dans le cadre de l'optimisation de la thérapie de resynchronisation cardiaque (CRT). Des descripteurs locaux du couplage électromécanique cardiaque sont extraits à partir d'informations anatomiques, fonctionnelles, électriques et mécaniques issues de volumes scanner (CT), d'échocardiographie par ''speckle tracking'' (US) et de cartographies électroanatomiques (EAM). L'approche proposée repose sur le recalage des données multimodales sur un modèle 3D+t du ventricule gauche (VG) calculé à partir de surfaces segmentées. Cette approche procède en deux temps : (1) un recalage semi-interactif des données EAM et d'images CT ; (2) un recalage de données US avec le modèle dynamique pour lequel les deux méthodes automatiques (statique et dynamique) ont été développées. Ces techniques intègrent un mode de projection radiale et une interpolation de mise en correspondance temporelle (par Dynamic Time Warping) des données EAM et US. Ces méthodes offrent la possibilité de calculer, sous différents modes de simulation cardiaque, les délais d'activation électrique, les cartes de voltage, les délais mécaniques et les délais électromécaniques locaux. La visualisation (cartographies 3D et 2D) de ces descripteurs permet de caractériser le couplage électromécanique intra-segments du VG. Ces méthodes ont été appliquées sur données simulées et réelles. Elles ont montré leur pertinence quant à la possibilité d'extraire des descripteurs locaux de la fonction cardiaque significatifs pour l'optimisation de la pose de stimulateur en CRT.
34

Extraction de métabolites du lichen "Pseudevernia furfuracea" via la technologie des liquides ioniques sous irradiation micro-onde / Extraction of metabolites of lichen "Pseudevernia furfuracea" via ionic liquids technology under microwave irradiation

Komaty, Sarah 02 July 2014 (has links)
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.
35

First Principles-Based Interatomic Potentials for Modeling the Body-Centered Cubic Metals V, Nb, Ta, Mo, and W

Fellinger, Michael Richard 23 July 2013 (has links)
No description available.
36

Arbetarrörelsen inom den radikala konstmusikens tankekollektiv : En studie av relationen mellan det radikala musiklivet och arbetarrörelsen under svenskt 1960-tal / Labourism within the Thought Collective of Radical Art Music : A Study of the Relationship between the Radical Music Scene and the Labour Movement in Sweden during the 1960s

Petersson, Tobias January 2014 (has links)
Subject of this study is the evolvement of the radical art music scene in Sweden. In this development took the labour movement an active part during the 1960s. The purpose of this study is to examine how the relationship between the radical art music scene and the labour movement was constituted and what this relationship implied for the Swedish radical art music scene during the 1960s. During the 1960s radical music became an influencial part in the Swedish music scene of modern art music. In this development the artists’ society Fylkingen had a central position. In the early 1960s Fylkingen began to incorporate writers, engineers, scientists, sociologists, philosophers, economists, etc. in their work and a number of projects were initiated which interacted with common society. A proposal for a public record company was developed together with KSF (Social Democratic Association for Cultural Workers) and was presented to the Swedish parliament. In collaboration with ABF (Workers’ Educational Association) the first studio for electronic music was build in 1960 and the relationship between the labour movement and the radical art music scene was institutionalized as the Stockholm Electronic Music Studio Foundation. This thesis uses the terminology of Ludwik Fleck to examine the relationship between the radical art music scene and the labour movement. The concepts of Thought collective and Thought-style are used to draw conclusions about common values and objectives within the Thought-style. The radical art music scene and the labour movement are understood to be part of a common Thought collective with a common style of thought. Because of this relationship, projects initiated in the radical music scene came to emphasize the democratic and educational aspects of music. In the latter half of the 1960s it was conceived impossible to achieve these goals under the existing program, leading to the notion within the style of thought that technological advancement was a prerequisite for a democratic music scene.
37

Optimering av underhållssystem för luftkvalitet i Hamreskolan / Optimization of the maintenance system for air quality in Hamreskolan

Askar, Maryam, Svärdelid Fichera, Davide January 2022 (has links)
Teknik och fastighetsförvaltningen är en förvaltning inom Västerås stad som ansvarar för byggandet av Västerås stad. Förvaltningen är intresserad av att få en bredare kunskap om optimering av underhållssystem för luftkvalitet och hur det skulle leda till energibesparing. Uppkomsten till deras intresse för om optimering av underhållssystem för luftkvalitet och energibesparing, är av anledning att de söker nya innovativa möjligheter att optimera luftkvalitet inom deras befintliga och nya fastigheter inom Västerås stads kommun. Projektgruppen samt teknik och fastighetsförvaltningen valde att lägga fokus på Hamreskolan där de i dagsläget har ett gediget underhållssystem för luftkvaliteten men har en önskan till förbättring. Skälet är deras upplevelse av luftkvalitet som inte är optimal, upplevelsen är att man känner sig trött, att det är kallt och kvavt ibland även för varmt inne i lokalerna. Bra luftkvalite är väsentligt för det påverkar både personalen och eleverna prestationsförmåga prioriterades detta. Målet med detta examensarbete är att presentera förbättringsförslag för att optimera underhållssystemet i Hamreskolan. Underhållssystemet innefattar ventilationssystemet och styrsystemet där dess syfte är att underhålla luftkvaliteten. De metoder som användes för framtagandet av förbättrings förslagen är djup litteraturstudie, platsbesök i Hamreskolan, brainstorming med förvaltare från Teknik och fastighetsförvaltningen samt pugh matris för validering av förbättrings förslagen. I detta examensarbete presenteras och diskuteras de förbättringsförslag som kommer medföra positiva effekter för Hamreskolan vid implementation. Dessa förbättringsförslag behövs inte nödvändigtvist begränsas till endast implementation vid Hamreskolan, det går även att implementera vid flera fastigheter inom Västerås stad, Teknik och fastighetsförvaltning. Vid utvecklande av förbättringsförslagen har realitet för funktionalitet och dess effekt vid implementation i Hamreskolan varit i åtanken. / Technology and property management is an administration within the city of Västerås that is responsible for the construction of the city of Västerås. The administration is interested in gaining a broader knowledge of optimizing maintenance systems for air quality and how it would lead to energy savings. The emergence of their interest in optimizing maintenance systems for air quality and energy savings, is due to seeking new innovative opportunities to optimize air quality within their existing and new properties within the City of Västerås. The project group as well as technology and property management chose to focus on Hamreskolan, where they currently have a solid maintenance system for air quality but have a desire for improvement. The reason is their experience of air quality which is not optimal, the experience is that you feel tired, that it is cold and sometimes even too hot inside the premises. Good air quality is essential because it affects both the staff and the student's performance priorities. The aim of this thesis is to present improvement proposals to optimize the maintenance system in Hamreskolan. The maintenance system includes the ventilation system and the control system where its purpose is to maintain the air quality. The methods used for the preparation of improvement proposals are in-depth literature study, site visits to Hamreskolan, brainstorming with managers from Technology and Property Management and a pugh matrix for validation of improvement proposals. In this thesis, the improvement proposals that will have positive effects for Hamreskolan upon implementation are presented and discussed. These improvement proposals do not necessarily have to be limited to only implementation at Hamreskolan, it is also possible to implement at several properties within the City of Västerås, Technology and property management. In developing the improvement proposals, the reality for functionality and its effect when implemented in Hamreskolan has been in mind.
38

Fallstudie om Prediktivt och Tillståndsbaserat Underhåll inom Läkemedelsindustrin / Case study regarding Predictive and Condition-based Maintenance in the Pharmaceutical Industry

Redzovic, Numan, Malki, Anton January 2022 (has links)
Underhåll är en aktivitet som varje produktion vill undvika så mycket som möjligt på grund av kostnaderna och tiden som anknyts till den. Trots detta så är en väl fungerande underhållsverksamhet väsentlig för att främja produktionens funktionssäkerhet och tillgänglighet att tillverka. En effektiv underhållsorganisation går däremot inte ut på att genomföra mer underhåll än vad som egentligen är nödvändigt utan att genomföra underhåll i rätt tid. På traditionellt sätt så genomförs detta genom att ersätta slitage delar och serva utrustningen med fastställda mellanrum för att förebygga att haveri, vilket kallas för förebyggande underhåll. De tidsintervaller som angivits för service bestäms av leverantörerna och grundar sig i en generell uppskattning av slitagedelarnas livslängd utifrån tester och analys. Till skillnad från att köra utrustningen till den går sönder som kallas för Avhjälpande underhåll så kan underhåll genomföras vid lämpliga tider så att det inte påverkar produktion och tillgänglighet. Men de tidsintervall som leverantörerna rekommenderar till företagen garanterar inte att slitage delen håller sig till det intervallet, delarna kan exempelvis rasa tidigare än angivet eller till och med hålla längre. Av denna anledning är det naturliga steget i underhållets utveckling att kunna övervaka utrustningens hälsa i hopp om att kunna förutspå när och varför ett haveri ska uppstå. Den här typen av underhåll kallas för tillståndsbaserat och prediktivt underhåll och medför ultimat tillgänglighet av utrustning och den mest kostnadseffektiva underhållsorganisationen, då god framförhållning och översikt uppnås för att enbart genomföra underhåll när det behövs. Det som gör tillståndsbaserat och prediktivt underhåll möjligt är den fjärde industriella revolutionen “Industri 4.0” och teknologierna som associeras med den som går ut på absolut digitalisering av produktionen och smarta fabriker. Teknologier som IoT, Big Dataanalys och Artificiell Intelligens används för att koppla upp utrustning till nätet med hjälp av givare för att samla in och lagra data som ska användas i analyser för att prognosera dess livslängd. Uppdragsgivaren AstraZeneca i Södertälje tillverkar olika typer av läkemedel som många är livsviktiga för de patienter som tar dessa mediciner. Om AstraZenecas produktion står still på grund av fel i utrustningen kommer det inte enbart medföra stora ekonomiska konsekvenser utan även påverka de människor som med livet förlitar sig på den medicin som levereras. För att försäkra produktionens tillgänglighet har AstraZeneca gjort försök att tillämpa tillståndsbaserat och prediktivt underhåll men det är fortfarande enbart i startgroparna. Eftersom ventilation är kritisk del av AstraZeneca produktion då ett fel i ventilationssystemet resulterar i totalt produktionsstopp i byggnaden förens problemet åtgärdas och anläggningen sanerats blev det även rapportens fokusområde. Arbetets uppgift går därför ut på att undersöka möjligheter för AstraZeneca att utveckla deras prediktiva och tillståndsbaserat underhåll på deras ventilationssystem, för att sedan kunna identifiera och presentera förslag på åtgärder. Dessa förslag analyserades sedan med hjälp av verktygen QFD-Matris och Pugh-Matris för att kunna uppskatta vilket förslag som är mest kostnadseffektivt, funktions effektivt samt vilket förslag som kommer tillföra mest nytta för underhållet på AstraZeneca. / Maintenance is an activity that every production wants to avoid as much as possible due to the costs and the time associated with it. Despite this, a well-functioning maintenance operation is essential to promote the production's availability to manufacture and operational reliability. Running an efficient maintenance operation is not about carrying out more maintenance than is necessary but carrying out the right amount of maintenance at the right time. Traditionally speaking this is done by replacing worn parts and servicing the equipment at set intervals to prevent breakdowns, this method is called preventive maintenance. The intervals specified for service are determined by the suppliers and are based on general estimates of the service life for the spare parts from test and analytics. Preventive maintenance allows for maintenance to be carried out at appropriate time to not affect production and availability unlike running the equipment until breakdown, which is called reactive maintenance. However, these intervals that the suppliers recommend do not guarantee that the parts adhere to the given interval, the part can for example break down earlier than expected or even outlast its prescribed lifetime. Because of this, the natural step in the development of maintenance is giving companies the ability to monitor the health of the equipment in hope of being able to predict potential breakdowns. This is what Condition-Based and predictive maintenance is and it provides the ultimate availability of equipment and the most cost-effective maintenance organization, because the good foresight and overview allows maintenance to be carried out only when needed. The fourth industrial revolution “Industry 4.0”, absolute digitalization of production, smart factories and all the technologies associated with this is what makes this type of maintenance possible. Technologies such as IoT, Big Data Analytics and Artificial Intelligence are used to connect equipment to the network using sensors so that data can be stored and collected to be analyzed to forecast the lifespan of parts and equipment. AstraZeneca in Södertälje manufactures different types of medicine, many of which are vital for the patients who take them. If their production comes to a standstill due to equipment failure, it will not only have major financial consequences but also greatly affect the people who rely on the medicine offered with their lives. To ensure the availability of production, AstraZeneca has made attempts to apply condition-based and predictive maintenance, but it is still only in its infancy. Since ventilation is a critical part of AstraZeneca's production, as a failure here will result in a total production stoppage for the building affected and will not resume before the problem is remedied and the plant is decontaminated, it also became the report's focus area. The task at hand is therefore to investigate the opportunities AstraZeneca must develop their predictive and condition-based maintenance for their ventilation systems, in order to be able to present proposals for measures. The proposals will then be analyzed using tools like the QFD-Matrix and the Pugh-Matrix in order to estimate which is more cost effective, function effective and which one will bring the most benefit to AstraZeneca.
39

Émetteurs achromatiques pour le réseau d'accès optique haut débit multiplexé en longueurs d'onde

Nguyen, Quoc Thai 21 January 2011 (has links) (PDF)
Cette thèse s'inscrit dans le contexte de la forte évolution du réseau d'abonnées sur fibre optique (FTTH). Elle a l'objectif d'étudier les solutions d'émetteurs dits "achromatiques" à base de nouveaux composants optoélectroniques pour les réseaux d'accès optiques multiplexés en longueurs d'onde (WDM-PON). Ces émetteurs doivent être peu chers et identiques chez tout abonné quelque soit la longueur d'onde de fonctionnement. Deux types d'émetteurs achromatiques à base de modulateur réflectif sont étudiés dans cette thèse : le laser Fabry-Perot verrouillé par injection optique (IL-FP) et le modulateur électro-absorbant amplifié en réflexion (R-EAM-SOA). Les caractéristiques de l'IL-FP en régime de verrouillage sont évaluées en termes de bruit d'intensité, de modulation, de facteur de couplage phase-amplitude,... La caractérisation tant statique que dynamique est aussi effectuée pour le second composant R-EAM-SOA. D'autres fonctionnalités de ce composant comme la détection directe et la régénération promettent son grand potentiel pour la réalisation d'un dispositif multifonctionnel pour le réseau d'accès. Il est également proposé d'utiliser pour la première fois, le laser à bâtonnets quantiques à blocage de modes (QD-MLL) comme source d'injection multi-longueurs d'onde cohérentes pour l'accès optique WDM. Il est montré qu'il est possible de supprimer le bruit de partition de modes associé à ces structures à blocage de modes. Finalement l'intégration de ces trois composants dans des architectures WDM-PON est réalisée. La faisabilité des systèmes WDM-PON à 2,5 Gb/s à base des IL-FP injectés par une source QD-MLL est évaluée pour différentes configurations et architectures réseau. La montée en débit à 10 Gb/s est prouvée en utilisant le R-EAM-SOA. Un système WDM-PON bidirectionnel avec une capacité de 240 (24 x 10) Gb/s en voie descendante et 60 (24 x 2,5) Gb/s en voie montante a été démontré en utilisant ces solutions d'émetteurs achromatiques proposées. Une des principales sources de dégradation du système WDM-PON bidirectionnel est la rétrodiffusion de Rayleigh pour laquelle le bruit interférométrique produit est étudié. L'impact de ce bruit sur les performances en transmission du système WDM-PON est aussi analysé.

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