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Aquisição rápida de imagens com técnicas tipo Echo Planar Imaging - Implementação das sequências EPI e SEPI. / Fast acquisition of images with techniques of type Echo Planar Imaging - Implementation of sequences EPI and SEPILucian Soares Bueno 18 June 2004 (has links)
O objetivo deste trabalho é o desenvolvimento e implementação de metodologias de imagens por Ressonância Magnética Nuclear, para diminuição do tempo de aquisição, já que nos exames clínicos convencionais esse tempo é muito superior ao utilizado nessas seqüências, que é da ordem de T_ 2 , essas seqüências são baseadas na varredura única do espaço-k, convencionalmente denominada Echo Planar Imaging. Os propósitos de utilização dessa metodologia compreendem desde exames clínicos convencionais, em que se pretende analisar, em projetos futuros, eventos não periódicos de curta duração e a dinâmica dos sistemas biológicos estudados, até imagens de cavidades utilizando gases hiperpolarizados. As técnicas implementadas em comparação com as inicialmente propostas por Masfield apresentam uma diferença que é a inexistência do pulso de RF de inversão e, com isso, o tempo de duração das seqüências implementadas é ainda menor. Apenas não se deve esperar muito da qualidade das imagens sem o pós-processamento, uma vez que esse trabalho já está em andamento. / The objective of this work is the development and implementation of methodologies of images for Nuclear Magnetic Resonance, for reduction of the time of acquisition, since in the conventional clinical examinations this time is very superior to the used one in these sequences, that are of the order of T_ 2 , these sequences is based on the only sweepings of the space-k, conventionally called Echo Planar Imaging. The intentions of use of this methodology understand since conventional clinical examinations, where if it intends to analyze, in future projects, not periodic events of short duration and the dynamics of the biological systems studied, until socket images using hiperpolarizados gases. The techniques implemented in comparison with initially the proposals for Masfield present a difference that is the inexistence of the pulse of RF of inversion and, with this, the time of duration of the implemented sequences are still lesser. But if it does not have to wait very of the quality of the images without the after-processing, a time that this work already is in progress.
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Artefatos em ferro de origem terrestre : um estudo de caso sobre a interface entre pesquisa arqueológica e conservação no sítio Charqueada Santa Bárbara, Pelotas, RS, BrasilVasconcelos, Mara Lúcia Carrett de 25 March 2014 (has links)
The current state of degradation of most archaeological collections has compromised the
research and protection of this heritage. To respond to these problems, some initiatives that
seek to modify the current practices of preservation of archaeological collections are
emerging, as the fieldwork in the Charqueada Santa Barbara archaeological site ( Pelotas, RS,
Brazil ), linked to the research project Pampa Negro: Arqueologia da Escravidão na Região
Sul do Rio Grande do Sul (1780-1888), which has brought together a multidisciplinary team
to talk about the praxis of each area and to think of appropriate solutions for the better
management and protection of archaeological collections. In the context of the conservation,
protocols for preventive and curative intervention of different types of materials were
developed and tested in field and laboratory. Among the types of material recovered in the
excavation, metal objects, especially iron, are those most susceptible to deterioration due to
the process of recovery and to the speed at which the corrosive processes occur as well as the
complexity of the products resulting from these. In this context, the aim of this study was to
analyze, from a study of the interface between conservation and archeology, how the
conservation procedures performed in the field and laboratory in the ferrous artifacts
contributed to the preservation of archaeological collections. It was expected to verify which
interventions enable a better conservation of archaeological origin and of the associated
information material culture, and disseminate the need for greater integration between the
experts related to the safeguard of the archaeological heritage areas. It was concluded that
conservation practices directly assist in the preservation of archaeological collections in its
material, documentary and symbolic aspects. Therefore, the conservator has become more of a manager of these collections, in a performance that, increasingly, is turning into an agent
crucial to the management of the archaeological heritage. / O estado atual de degradação de grande parte dos acervos arqueológicos tem comprometido
as pesquisas e a salvaguarda destes bens. Destas problemáticas vêm surgindo iniciativas que
buscam a modificação das práticas atuais de preservação dos acervos arqueológicos, como o
trabalho de campo do sítio Charqueada Santa Bárbara (Pelotas, RS, Brasil), vinculado ao
projeto O Pampa Negro: Arqueologia da Escravidão na Região Meridional do Rio Grande
do Sul (1780-1888), que reuniu uma equipe multidisciplinar a fim de dialogar a respeito da
práxis de cada área e pensar de forma conjunta soluções adequadas para um melhor
gerenciamento e salvaguarda dos acervos arqueológicos. No âmbito da conservação, foram
elaborados e testados em campo e em laboratório protocolos de intervenção preventiva e
curativa para distintos materiais. Dentre os materiais recuperados na escavação, os objetos
metálicos, em especial os de ferro, estão entre aqueles mais suscetíveis à deterioração
decorrente deste processo, em função da velocidade em que ocorrem os processos corrosivos
e da complexidade destes. Neste contexto, o objetivo da presente pesquisa foi analisar, a partir
de um estudo da interface entre Conservação e Arqueologia, de que forma os procedimentos
de conservação realizados em campo e em laboratório nos artefatos em ferro contribuíram
para a preservação dos acervos arqueológicos. Almejou-se verificar as intervenções que
possibilitam a melhor conservação da cultura material de origem arqueológica e da
informação associada, e difundir a necessidade de uma maior integração entre os especialistas
das áreas relacionadas à salvaguarda do patrimônio arqueológico. Concluiu-se que as práticas
de conservação auxiliam diretamente na preservação dos acervos arqueológicos, em suas
instâncias material, documental e simbólica. O conservador vem se configurando, portanto,
como mais um gestor destes bens, em uma atuação que, cada vez mais, se torna indispensável
ao gerenciamento do patrimônio arqueológico.
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How to support and enhance communication : in a student software development project / Hur man stöder och förstärker kommunikation : i ett studentdrivet mjukvaruutvecklingsprojektAhlström, Catharina, Fridensköld, Kristina January 2002 (has links)
This report, in which we have put an emphasis on the word communication, is based on a student software development project conducted during spring 2002. We describe how the use of design tools plays a key role in supporting communication in group activities and to what extent communication can be supported and enhanced by tools such as mock-ups and metaphors in a group project. We also describe a design progress from initial sketches to a final mock-up of a GUI for a postcard demo application. / I denna rapport, som baserar sig på ett studentprojekt utfört under våren 2002, har vi fokuserat på ordet kommunikation. Vi beskriver hur användande av designverktyg kan spela en nyckelroll när det gäller att stöda kommunikation i gruppaktiviteter och i vilken utsträckning kommunikation kan stödas och förstärkas av verktyg som mockuper och metaforer. Vi beskriver också en designprogress från initiala skisser till färdig mockup av ett grafiskt användargränssnitt för en demoapplikation av en vykortstjänst.
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Suburban Swedish maturing : Examining variation and perceptions among adult speakers of Swedish contemporary urban vernacular / Förortssvenskan på mognadsvägen : En undersökning av variation och perceptioner bland vuxna talare av svensk ‘contemporary urban vernacular’Young, Nathan January 2014 (has links)
Up to now, adolescent speakers have been the primary focus when researching contemporary variation in the language of Sweden’s urban areas. This study contributes to the growing body of research on the topic by examining and reporting on adult speakers of what is here referred to as förortssvenska (English: Suburban Swedish). This study focuses specifically on formal speech registers of eight young working-class men from Stockholm along with the perception and reception of their speech by two independent native-listener groups. The paper is the first to present quantifiable data on what has been previously referred to as a “staccato” rhythm in Suburban Swedish. Strong correlations are shown between prosodic rhythm as measured by the normalized pairwise variability index (nPVI) and speech speed to mean listener attitudes (R2=0.9). A strong correlation is also shown for nPVI’s influence on mean listener-projected ethnicity (R2=0.8). Alongside variation in rhythm, we also see phonemic variation that trends toward specific indexes of social identity as revealed by speaker interviews and native-listener assessments. Alongside linguistic variation among speakers, there is also significant variation within speaker peer groups. In addition to identifying specific linguistic features, the study examines social mechanisms revealed in interviews with and qualitative observations of speaker and listener participants. In exploratory fashion, ideas on variation, register ranges, meta-pragmatic stereotyping, and ethnic boundary-making are presented to make a case for treating contemporary urban variation in Swedish as a habitual semiotic extension of speaker identity. Indicators that contemporary urban variation in Swedish may be heading in the direction of sociolectal entrenchment are also discussed. / Hittills har unga talare varit det primära fokus för forskning av aktuell språklig variation i urbana Sverige. Denna studie bidrar till den växande mängden forskning i detta ämne genom att undersöka och rapportera om vuxna talare av det som här kallas för förortssvenska. Studien fokuserar specifikt på formella talregister bland åtta unga män från Stockholms arbetarklass, samt perception och mottagande av deras tal av två oberoende grupper av infödda lyssnare. Denna studie är den första som presenterar kvantifierbar data rörande den i tidigare forskning så kallade stackato-rytmen i förortssvenska. Starka korrelationer finns mellan, å ena sidan, prosodisk rytm mätt med the normalized pairwise variability index (nPVI) och talhastighet och, å den andra, de genomsnittliga lyssnarattityderna (R2=0,9). Det finns också en stark korrelation för nPVIs påverkan på genomsnittlig lyssnarprojicerad etnicitet (R2=0,8). Vid sidan av variation i rytm ser vi också fonemisk variation som trender mot specifika index för social identitet. Och vid sidan av variation i rytm bland talarna, finns också en stor variation inom kamratgrupperna. Förutom att den identifierar specifika lingvistiska drag, undersöker studien sociala mekanismer som framkommer i intervjuer med och kvalitativa observationer av talardeltagarna och lyssnardeltagarna. På ett explorativt sätt, lägger studien fram idéer om variation, registeromfång, meta-pragmatiska stereotyper och etniska gränsskapande för att framhäva argumentet för att behandla den aktuella förortsvariationen i svenska som en habituell avsiktlig utbyggnad av talarens identitet. Det diskuteras också indikatorer till att den aktuella urbana variationen i svenska kan vara på väg mot sociolektal stabilisering.
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Développement de méthodes de caractérisation chimiques de surface en support à l’amélioration des procédés de la microélectronique avancée / Development of surface analysis chemical characterization methods making possible to improve processes in advanced microelectronicsJames, Anthony 09 July 2015 (has links)
L'objectif principal de ce travail de thèse a été de développer des méthodologies d'analyse de surface fiables pour caractériser divers nouveaux matériaux intégrés dans des structures de très faibles dimensions caractéristiques des développements actuels de la microélectronique. Un intérêt particulier a été porté sur l'utilisation combinée de plusieurs techniques complémentaires. Une première étude a porté sur les artefacts de caractérisation de couches isolantes (dioxyde de silicium et dioxyde de silicium dopé au fluor – FTEOS) situées entre les niveaux de métallisation des puces. Une étude systématique des effets de la dose électronique liée à une analyse AES a été réalisée en utilisant la complémentarité des techniques AES/XPS. Les résultats ont révélé des changements chimiques en extrême surface (sous-oxydes) dépendant de la nature du matériau. La seconde étude a porté sur la mise en oeuvre d'une méthodologie analytique pour la caractérisation de la couche de passivation formée sur les flancs de gravure après deux gravures plasma successives sur des structures de très faibles dimensions (lignes de 300 nm et tranchées de 200 nm). Cette méthodologie a été basée sur l'utilisation de l'effet de charge différentiel, observé lors d‘analyses simultanées de deux matériaux de propriétés électriques différentes, ainsi que sur la complémentarité des caractérisations par XPS et ToF-SIMS y compris des analyses XPS résolues en angles (AR-XPS). La composition chimique de l'extrême surface de la couche de passivation a ainsi pu être déterminée sur des parois verticales. La surface de cette couche a révélé être composée principalement par de l'oxygène ayant réagi avec le silicium pour former des sous-oxydes de silicium de différentes stoechiométries / The main goal of this thesis was to develop reliable surface analysis methods to characterize various new materials used in very small size structures typical of current developments in microelectronics applications. A particular interest has been taken in combining several complementary techniques. The first study was focused on potential artifacts when characterizing insulating layers (silicon dioxide and fluorine doped silicon dioxide – FTEOS) which are used between metal layers in chips. A comprehensive study of the electron dose effects in AES was performed using complementary AES and XPS techniques. The results revealed chemical changes in the outermost surface (suboxides) that depend on the nature of the material. The second study was focused on the development of an analytical methodology to characterize the passivation layer on the etch sidewalls after two successive plasma etching processes applied onto very small size structures (300 nm lines and 200 nm trenches). This methodology was based on the use of the differential charging effect that takes place when analyzing simultaneously two materials exhibiting different electrical properties and on the complementarity of ToF-SIMS and XPS characterizations including angular resolved XPS (AR-XPS). The chemical composition of the outermost surface of the sidewall passivation layer could then be determined. The surface of that layer was found to be consisting mostly from oxygen than reacted with silicon to form silicon suboxides with various stoichiometries
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Quel(s) tropisme(s) atlantique(s) pour les cultures de la péninsule ibérique ? : le mobilier métallique du XIIIe au VIIIe a.C. : entre innovation et tradition / Which atlantic tropism for the cultures of the Iberian Peninsula ? : the study of the metallic artifacts from the XIIIth a.C. to the VIllth a.C.Pérez, Claire 20 December 2013 (has links)
Dans l'historiographie de l'âge du Bronze final, le tiers ouest de la péninsule Ibérique est considéré comme une province atlantique, qui interagit avec les autres "membres" du complexe atlantique, c'est-à-dire, les territoires de la France, de la Grande-Bretagne et de l'Irlande principalement. Dans ce réseau, les populations échangeraient individus, objets, idées et savoir-faire ; elles créeraient ainsi un espace délimité par la présence d'un lot d'artefacts communs (des outils, des armes, de la parure...) et par des pratiques communes (le festin, la déposition d'objets métalliques, etc.). Il est à noter que pratiques funéraires, architecture de l'habitat et matériel céramique sont de nature différentes et ont très tôt été exclus de cette définition, empêchant de qualifier cet ensemble de culture homogène. Un premier constat concernant la dispersion du mobilier métallique, réputé de types atlantiques, démontre qu'il existe en péninsule Ibérique des réseaux d'échanges puissants entre l'Atlantique et la Méditerranée, qui amènent à questionner le rôle et la place du territoire au sein du "complexe atlantique" européen. Ces remarques naissent d'un regard nouveau porté au vestige archéologique et amènent à questionner l'existence d'un faciès atlantique en péninsule Ibérique, et peut-être même en Europe. L'analyse des correspondances multiples, qui consiste à confronter plusieurs paramètres, répond à ce besoin de considérer le vestige archéologique comme un objet fonctionnel, fabriqué et utilisé par des hommes de l'âge du Bronze final. Dans le cas des épées, des haches et des pointes de lance, il s'agit de relever des critères quantitatifs et qualitatifs qui seront comparés successivement les uns avec les autres. L'objectif est de répondre à une série de questions précises, déterminées par des hypothèses relatives à la fabrication, à la fonction et à l'usage de l'objet. Ce travail est développé en trois temps qui se veulent les reflets des différents questionnements mis en place dès l'introduction. Le premier chapitre présente les enjeux du débat et la question principale qui oriente l'argumentation : Existe-t-il un faciès atlantique ? Le deuxième chapitre est dédié à l'étude des objets, particulièrement les épées, les haches et les pointes de lance. Cette étude rend compte du traitement statistique effectué mais également de l'analyse technique et fonctionnelle des objets. Le troisième chapitre constitue la synthèse de ces différentes approches et propose plusieurs éléments de réponse à la question de départ : existe-t-il un faciès atlantique en péninsule Ibérique ? / In the MBA and LBA historiography, the west lands of Europe - Great-Britain, Ireland, France and Iberian Peninsula - are gathered under the name "Atlantic complex". In this network, populations trade artifacts, ideas and Knowledge. Thus, they create a territory delimited by a set of communal artifacts (tools, weapons, jewellery, etc.) and by communal practices like feasts and hoards. It should be noted that burial practices, domestic architecture or potteries are of different natures, which make it impossible to call it an homogeneous culture. Since a few years, we wonder about the existence of this complex and we try to identify its features. How can we define a culture? How can we identify economic, technical or cultural areas? Does the Atlantic complex really exist? In order to answer these questions, the study of the Iberian Peninsula proved very interesting. The discovery of metallics artifact known as atlantic types let us think that Peninsula was an atlantic territory. However, facing the differences between artifacts from Peninsula and GB or France, we are allowed to challenge the existence of this complex. I propose here another approach of the Atlantic world, based on metallic artifacts found in the Iberian Peninsula. This work will be held in three parts. In the first part, I will show the problems of this work by presenting a short historiography of the methodology and its limits. I will then propose a new approach, elaborated upon my PHD work. In the second part, i will present three examples of this new approach: swords, axes and spearheads from the Iberian Peninsula. Finally, I will try to answer the question at issue : Does the Atlantic complex exist in The Iberian peninsula and in Europe in general ?
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De fem enkla maskinernas integrerande i den fria leken inom förskolans arena : En studie baserad på barns undersökande av enkel teknik i den fria leken. / “The Big Five’s” integration in the free play in preschool arena : A study based on children's exploration of simple technology in the free play.Andersson, Erika January 2017 (has links)
Studiens syfte är att påvisa hur barn tillämpar enkel teknik i förskolan genom de fem enkla maskinerna. Observationer och”Intervju i farten” är de metodval som besvarar studiens syfte och frågeställningar. Observationer och intervjuer har genomförts i förskolans utemiljö under en förmiddag och utgår från barnens fria lek där målet är att utgå ifrån barnens perspektiv och reflektioner. Situationerna som blivit valda till studien baseras av barnens nyfikenhet och påvisade intressen. Resultatet i studien visar att två av de fem enkla maskinerna tillämpas av barnen i förskolans utemiljö och fria lek. Detta synliggörs genom deras användning av lutande planet och hjulet ur de fem enkla maskinerna. Det sker genom användning av redskap, som utforskande, del av leken och genom begrepp. Detta sker genom ett sociokulturellt perspektiv där olika faktorer påverkar barnens lärande. / The purpose of the study is to demonstrate how children apply simple technology in preschool through “The Big Five”. Observations and "Interview on the move" are the method choices that answer the purpose and questions of the study. Observations and interviews have been conducted in the preschool outdoor environment during a morning and are based on the children's free play where the aim is to start from the children's perspective and reflections. The situations that have been chosen for the study are based on the children's curiosity and demonstrated interests. The result of the study shows that two of “The Big Five” are applied by the children in the preschool outdoor environment and free play. This is demonstrated by their use of the leaning plane and the wheel from “The Big Five”. It shows by their use of tools such as exploration, part of the game and through concepts. This is done through a sociocultural perspective where different factors influence children's learning.
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Mapování pohybových artefaktů ve fMRI / Mapping of motion artefact in fMRINováková, Marie January 2013 (has links)
This thesis summarizes a theory of magnetic resonance and the method of functional magnetic resonance. It is focused on the influence of motion artifacts and image preprocessing methods, especially realign. It deals with the possibility of using movement parameters obtained in the process of alignment of functional scans to create maps that show the expression of motion artifacts. In this thesis, three different methods were designed, implemented a tested. These methods lead to the creation of probability, power and statistical group maps showing areas typically affected by movement artifacts.
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Nové přístupy pro optická měření elektrické aktivity myokardu / New Approaches in Cardiac Optical MappingŠvrček, Martin January 2011 (has links)
This dissertation deals with new approaches in cardiac optical mapping. The principle of cardiac optical mapping as well as the current research in this field was described. The new measurement system was developed and its characteristics presented. The system design allows epicardial and endocardial mapping, employing new ratiometric techniques in 2D acquisition and simultaneous electrical and optical mapping. The measured characteristics of fluorescent dye di-4-ANEPPSS were presented. The relation between movement and consequent motion artifacts is well described. Several new approaches in signal processing were proposed, including new ratiometry technique and using image registration to suppress motion artifacts. The algorithm for elastic image registration of optical signals and innovative method for verification of registration process were presented. Application of all proposed approaches and its results are included and discussed.
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Redukce korozních vrstev mosazi pomocí nízkotlakého nízkoteplotního plazmatu / Brass Corrosion Layers Reduction by Low-Pressure Low-Temperature PlasmaŘádková, Lucie January 2015 (has links)
This thesis presents results of the corrosion layers removal which could be found on the archaeological artefact surfaces. The low pressure low temperature plasma reduction was used for this purpose. Brass samples were chosen for this study. Two different ways have been used to form model corrosion layers. Several sets of corrosion layers were prepared in laboratory in two different corrosion atmospheres, namely ammonia atmosphere and atmosphere of hydrochloric acid. These samples were placed into desiccator. Small quantities of sand were added to some sets of samples so samples with sandy incrustation were prepared. The corrosion layers had been usually formed during four weeks. The second way, which was used to prepare model corrosion layer, was the natural corrosion in soil or compost. In this case, the corrosion layers had been formed approximately 2 years. The samples were treated in the low pressure (150 Pa) cylindrical Quartz reactor (90 cm long and 9.5 cm in diameter) with a pair of external copper electrodes connected via the matching network to a radiofrequency generator (13.56 MHz). The flows of working gases were set by independent mass flow controllers. Whole system was continuously pumped by the rotary oil pump which was separated from the discharge reactor by liquid nitrogen trap with aluminium chips eliminating dust and reactive species from the gas flow. Each sample was placed on a glass holder at the reactor center. Plasma was generated in pure hydrogen or in mixture of hydrogen and argon. Total flow of working gas was 50 sccm. Different ratios of gas mixture were tested, the ratio 30 sccm hydrogen and 20 sccm argon flows was the best. RF discharge was used in a continuous and pulsed regime. Pulsed mode was carried out with various duty cycle at the frequency of 1000 Hz. There were two ways of temperature monitoring. The sample temperature during the treatment was monitored by a K-type thermocouple installed inside the sample in the first case. Thermometer optical probe was connected to the sample surface by a small stainless plate and allowed continuous sample temperature monitoring in the second way. Safe object temperature for copper and copper alloys is 100–120 °C. To avoid exceeding this temperature, power control or the duty cycle in pulse mode were automatically controlled if thermometer optical probe was used. Plasma chemical treatment is based on generation of reactive atomic hydrogen in plasma discharge. The main reactions during reduction were reactions between oxygen and chloride contained in the corrosion layer and the hydrogen ions and neutral atoms generated in the plasma. These reactions create an unstable OH radical, which emits light in the region of 306–312 nm. This radiation was detected by the optical emission spectroscopy using Ocean Optics HR4000 spectrometer with 2400 gr/mm grating. Data obtained from this method were used to calculate rotational temperatures and integral intensity of OH radicals that were used for the process monitoring. Corrosion layer was not completely removed during the reduction, but due to the reactions which occur in the plasma corrosion layer became brittle and after plasma chemical treatment can be removed easily. The SEM-EDS material analyses were carried out before and after treatment of some samples. Some samples were analysed by XRD analysis. EDS analysis showed that amount of oxygen and chloride was decreased, mainly at 400 W pulse mode.
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