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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.
21

Changes in Quantitative EEG and Low Resolution Tomography Following Cranial Electrotherapy Stimulation.

Kennerly, Richard C. 08 1900 (has links)
The effects of cranial electrotherapy stimulation (CES) on human EEG and brain current density were evaluated by quantitative electroencephalography (qEEG) and low resolution brain electromagnetic tomography (LORETA). A total of 72 research subjects were provided with a single session of CES, 38 were provided with 0.5 Hz CES while 34 were provided with 100 Hz CES. The qEEG paired t-tests revealed that in both frequencies of CES there was a significant (.05) increase in alpha relative power with concomitant decreases in delta and beta relative power. The 0.5 Hz CES decreased a wider frequency range of delta activity, while the 100 Hz CES decreased a wider frequency range of beta activity; suggesting some difference may exist in the EEG response to different frequencies of CES. The changes found in qEEG relative power were consistent with the affective and cognitive effects of CES reported in the literature, such as increased relaxation and decreased anxiety. Statistically significant changes for qEEG values other than relative power, such as coherence, amplitude asymmetry, phase lag and power ratios were also found. The LORETA paired t-tests found statistically significant (.05) increases in cortical and subcortical theta and alpha frequency current density with concomitant decreases in delta and beta current density. The effects of CES on current density varied by frequency, but did not show a differential in response based on proximity to the contacts, or structures within the brain. Statistically significant changes in current density were found in all 2394 gray matter voxels represented by LORETA, indicating a whole brain response to the CES stimulus. The qEEG and LORETA findings revealed that a single 20-minute session of CES does have a significant effect on the cortical and subcortical activity of the human brain resulting in activity consistent with decreased anxiety and increased relaxation.
22

Diamanttetras utforskande beteende och stimformation i artificiell miljö : En jämförelse mellan odlade och vildfångade diamanttetror / Explorative behavior of diamond tetra and their shoal formation in artificial environment : A comparison between farmed and wild-captured diamond tetra

Melkerson, Sandra January 2020 (has links)
De har gjorts få studier på akvariesfiskars beteende. För att bemöta intresset för akvariefiskar så behöver vi veta mer om deras beteende i en artificiell miljö. Syftet med den här studien är att jämföra det utforskande beteendet hos vildfångade och odlade diamanttetror som är en vanlig akvariefisk. Hypotesen är att det finns en skillnad i deras beteende där vildfångade är mer djärva än de odlade. Grupper om fem individer av diamanttetra vildfångade och odlade släpptes ner i en ny artificiell miljö. De filmades i 20 minuter från de att de släpptes i. Testet upprepades 10 gånger med nya individer och för varje försök togs tiden det tog för varje individ att lämpa botten av akvariet och sedan mättes storleken på stimmen för varje grupp. Jag hittade en skillnad i hur lång tid fiskarna tog på sig för att lämna botten men det var ingen skillnad i höjd eller längd på stimmen. Detta visar att de vildfångade visade ett djärvare beteende än de odlade genom att lämna botten snabbare. Den här studien gav information om skillnaden i beteende för vildfångade och odlade diamanttetror och informationen kan användas för fortsatta studier kring akvariefisk. / The behaviour of ornamental fish is not well studied. To meet the needs of ornamental fish hobbyists, we need to know more about the behavior of fish in artificial environments. The aim of this study is to compare the explorative behaviour of wild-captured and farmed fish in a common ornamental fish, the diamond tetra. The hypothesis is that there is a difference between the two groups behavior where the wild-captured tetras are bolder. Groups of five individuals of farmed respectively wild-captured diamond tetra were released in a new artificial environment where they were monitored for 20 minutes. The test was repeated 10 times with new individuals, and the time it took for them to leave the bottom of the aquarium was measured as well as the size of the shoal. I found a difference in the time it took for the individuals to leave the bottom, with the wild-captured tetras leaving the bottom earlier than the farmed fish. There were no differences in height or length of the shoal. Thus, the wild diamond tetra were bolder than the farmed tetras. The study gave information about the differences in behavior between wild-captured and farmed diamond tetra and can give information to further studies about ornamental fish.
23

Ionenstrahluntersuchungen am Gelenkknorpel: Energiedispersive Röntgenspektrometrie, Rückstreuspektrometrie und Transmissionsionenmikroskopie (PIXE, RBS, STIM)

Reinert, Tilo 20 November 2001 (has links)
Knorpel ist ein kompliziertes System aus einem kollagenen Netzwerk, gefüllt mit wasserbindenden Makromolekülen (Proteoglykanen) und darin eingebetteten Zellen. Störungen in den komplexen Wechselbeziehungen können zur Gefährdung der strukturellen Integrität des Knorpels führen. Die hochauflösende Magnetresonanztomographie (NMR-Mikroskopie) kann über die Analyse der Signalintensität interne Knorpelstrukturen darstellen (hypo- und hyperintense Zonen). Mit Hilfe ionenmikroskopischer Analysemethoden (PIXE, RBS, ERDA) wurden im Knorpel (femorale und tibiale Kondyle des Hausschweins) im Querschnitt die zweidimensionalen Verteilungen der Knorpelelemente (H, C, N, O, P, S, Cl, K und Ca) aufgenommen sowie die Konzentrationen in ausgewählten Zonen bestimmt. Ergänzend wurde mit STIM die Dichteverteilung im Knorpel untersucht. Es gelang auch mit STIM, erstmalig kollagene Fasern in ihrer, bis auf den Wasserentzug natürlichen, Umgebung im Knorpel und damit unverändert in ihrer Anordnung sichtbar zu machen (keine chemische Demaskierung nötig). Die Ergebnisse wurden mit NMR- und polarisationsmikroskopischen Untersuchungen verglichen und in ihrem Zusammenhang mit den histologischen Knorpelzonen diskutiert. In den NMR-hypointensen Zonen fanden sich eine erhöhte Chlorkonzentration und punktförmige Calciumanreicherungen. Diese Zonen waren (im gefriergetrockneten Zustand) durch eine, bis zu einem Faktor vier höhere Dichte gekennzeichnet, die im maximalen Gehalt der Matrixelemente, H, C, N, O, (höchste Kollagendichte) begründet liegt. Im tibialen Knorpel konnten in der NMR-hypointensen Zone radial verlaufende einzelne Kollagenfasern nachgewiesen werden. Im femoralen Knorpel wurden in dieser Zone keine Einzelfasern nachgewiesen. Es deutete sich eine tubuläre Anordnung der Kollagenfasern an. In der hypertrophen Zone zeigten sich hohe Konzentrationen an Phosphor (Zellorganellen), Schwefel (Proteoglykane), Kalium (alkalisches Milieu) und Calcium (Vorstufe der Kalzifizierung). Die Chlorkonzentration hatte dort ihr Minimum. In dieser Zone verlaufen die Kollagenfasern radial und münden senkrecht in den Kalkknorpel. In der Tangentialfaserschicht wurde eine erhöhte Konzentration an Calcium und Phosphor beobachtet (Einlagerung von Calciumphosphaten). In dieser Zone wurden tangential verlaufende Kollagenfasern und ihr Übergang zur stärkeren Vernetzung mit teilweise arkadenförmiger Überstruktur sichtbar gemacht. Zur genaueren Aufklärung der dreidimensionalen Anordnung der Kollagenen Strukturen wurden erste Experimente zur STIM-Tomographie durchgeführt.
24

Låtfabriken : En studie av upphovspersoners identifiering med sitt arbete i produktionsmusiksektorn

Alm, Sebastian, Axelsson, Max, Marquez Larsson, Denice January 2016 (has links)
Den här rapporten syftar till att undersöka hur upphovspersoner som sysselsätter sig med produktionsmusik identifierar sig med sitt komponerande och arbete, detta med hjälp av de organisationerna som de försörjer sig genom. De två organisationerna är STIM, Svenska Tonsättares Internationella Musikbyrå, eller Epidemic Sound. Skillnaden mellan de två organisationerna är huvudsakligen att hos STIM upplåter upphovspersonerna sitt verk till organisationen och de i sin tur får ansvaret att förvalta verket och samla in ersättning för upphovspersonens räkning, hos Epidemic Sound överlåter upphovspersonerna sitt verk för en engångsersättning. Epidemic Sound äger sedan verket och kan hyra ut musiken till olika produktionsbolag som vill ha musiken i sina produktioner. Till undersökningen har fyra kompositörer från STIM och fyra kompositörer från Epidemic Sound, samt en förläggare och en representant från STIM intervjuats. I rapporten framgår det att de som var anslutna till STIM har jobbat med musik länge, det är nästintill ett “kall” för dem, de ser verken som konstverk mer än som hantverk, de värdesätter upphovsrätten högt och ser ersättningen som en sekundär anledning till varför de sysselsätter sig med komponerandet. De från Epidemic Sound däremot ser sina verk mer som ett hantverk och den mer säkra lönen som går att få av Epidemic Sound är en stor anledning till varför de valt denna organisation. Med hjälp av organisations-, motivations och identitetsteorier har samband funnits mellan teorierna och val av ersättningsmodell. Denna studie påvisar att det skett en förändring på den svenska marknaden för produktionsmusik efter det att Epidemic Sound kom till år 2009. En förändring har skett gällande det institutionaliserade tillvägagångssättet att traditionellt licensera ut sin musik till produktionsbolag. Denna förändring har gett en ny typ av upphovspersoner med en annan arbetsidentitet en möjlighet att kunna försörja sig på sin musik. Detta har kunnat påvisas genom att studera hur upphovspersonerna identifierar sig med sitt arbete och komponerande beroende på vilken av modellerna de använder. / This essay aims to examine how composers who specializes in production music identify themselves with their composing and work, this with help from the organisations that they support themselves through. The two organisations are STIM, The Swedish Composers International Musicbureu, or Epidemic Sound. The difference between the two are mainly that with STIM the composers let them manage the administration and to collect their income with Epidemic Sound is that they sell their righs to Epidemic Sound for a flat-fee. Because of this transaction the composition is now owned by the company and they can rent it out to other production companies who would like to have the music in their productions. To the study four composers from STIM, four composers from Epidemic Sound, one publisher and one representative from STIM have been interviewed. In the report it emerges that the composers that are from STIM have worked with music for a long time, the work is almost like their destiny, they see their compositions as artwork than as a craftmanship, they put big value to the copyright law, and the commission is a secondary reason to why they do what they do. The composers for Epidemic Sound on the other hand see their work more like craftmanship and the more secure salary are the reason why the composers choose Epidemic Sound. With the help from organizational-, motivational- and identitybased theories connections has been made between the theories and revenue model. This study shows that there’s been a change within the swedish market for production music since Epidemic Sound was founded in 2009. A change has occurd regarding the institutionalized approach to traditionally license music to production companies. This change has given a new type of composers with another work identity an opportunity to provide themselves on their music. This has been detected by studying how the composers identify themselves with their work and their composing depending on what revenue model they choose.
25

Microestruturação de membranas de poli (tereftalato de etileno) por microfeixe de íons

Souza, Cláudia Telles de January 2013 (has links)
Neste trabalho, o processo de estruturação por microfeixe de íons foi utilizado para a produção de membranas microporosas em folhas comerciais de PET. O processo de estruturação por microfeixe de íons consiste basicamente na interação direta entre um feixe de íons de dimensões micrométricas com o material em questão. As zonas modificadas pelo feixe são removidas do restante do material através de um processo químico. Nesse contexto, durante o desenvolvimento deste trabalho, sistemáticas experimentais para o processo de estruturação foram desenvolvidas. Com o intuito de operacionalizar a linha de microfeixe presente no Laboratório de Implantação Iônica da UFRGS, foi necessário realizar um estudo aprofundado sobre o funcionamento de todo o sistema, verificando problemas e explorando a potencialidade de técnicas não convencionais de análise de materiais. O estudo sobre a sistemática de estruturação ocorreu através da investigação de parâmetros clássicos, como fluência utilizada durante a irradiação e tempo de ataque químico. Para atingir tais objetivos, amostras de poli (tereftalato de etileno) (Mylar) de 12 μm foram irradiadas com microfeixe de íons (H+ e He++) com energias de 3 e 2,2 MeV e fluências que variaram entre 1 x 1011 e 6 x 1015 íons/cm2. Posteriormente à irradiação, as amostras foram submetidas a um ataque químico com solução alcalina de hidróxido de sódio 6 M durante tempos que variaram de 0,5 à 60 minutos. A temperatura do ataque em todos os casos se manteve fixa em 60°C. A caracterização das amostras foi realizada através de microscopia eletrônica de varredura (MEV) e por microscopia de transmissão iônica (STIM). As amostras também foram caracterizadas através de medidas elétricas utilizando um circuito de corrente alternada. O processo de enxertia (grafting) foi testado nas membranas estruturadas, utilizando um hidrogel de PNIPAAm com concentrações de 0,340, 0,450 e 0,700 g/L. Tais resultados também foram analisados através de MEV. O estudo sobre a linha de microfeixe permitiu verificar a existência de problemas relacionados ao registro da carga elétrica durante as irradiações. Além disso, para o ajuste do foco do feixe de íons, foram feitas curvas de calibração de corrente para as lentes magnéticas considerando diferentes energias de feixe. O processo de estruturação através da técnica de microfeixe de íons se mostrou eficaz para a produção de estruturas regulares e definidas em folhas de PET. A fluência ótima de prótons a ser utilizada nos processos de estruturação foi estimada em 6 x 1014 íons/cm2. Para esta fluência, tempos de ataque químico inferiores a 1 minuto já são suficientes para corroer toda a parte irradiada. Entretanto, tempos um pouco mais longos (e.g. 2 minutos) tornam o processo mais reprodutível. Com relação à geometria das estruturas fabricadas, observou-se irregularidades em estruturas que, em princípio, deveriam ser simétricas. Esse problema foi atribuído à assimetria do feixe, proveniente de ajustes dos parâmetros de colimação do feixe. Finalmente, o estudo do processo de enxertia mostrou que o hidrogel adere nas paredes das estruturas, porém não as preenche. Para concentrações elevadas (e.g. 0,7 g/L) o processo não é tão eficiente, sendo que não é verificada a redução da área das microestruturas pela inserção do hidrogel. As medidas elétricas mostraram a existência de regimes distintos e dependentes da frequência da corrente alternada. Os polímeros apresentaram basicamente comportamentos resistivo e capacitivo. / In this work, the process of irradiation of PET foils with ion beams in the micrometer size range was used for the production of microporous membranes. Basically, this process consists on the direct interaction between the ion beam and the material under study. The regions modified by the beam are removed from the material through a chemical process. In this context, experimental procedures for the production process of the membranes were developed during the course of this work. In order to make the microbeam station of the Ion Implantation Laboratory of the Federal University of Rio Grande do Sul (UFRGS), it was necessary to perform a thorough study of the operational parameters of the system, thus allowing a proper identification of problems and providing grounds for pushing the technique to the frontier of materials science. To achieve such objectives, foils of polyethylene terephtalate (Mylar®) 12 μm thick were irradiated with H+ and He++ ions with 3 e 2,2 MeV respectively. Fluencies varied from 1 x 1011 and 6 x 1015 ions/cm2. After the irradiation, the foils were submitted to an etching procedure using alkaline solution of sodium hydroxide at 6 M during periods of time varying from 0,5 to 60 minutes. In all cases, the temperature of the etching was fixed at 60°C. The characterization of the samples was performed through scanning electron microscopy (SEM) and scanning transmission ion microscopy (STIM). The samples also were characterized by electric measurements using an AC current circuit. The process of grafting was tested on the structured membranes using a PNIPAAm hydrogel with concentrations of 0,340, 0,450 and 0,700 g/L. The results of this study were also analyzed through MEV. With the present study, it was possible to pinpoint problems related to the integration and recording of the charge during the irradiations. Besides that, calibration curves were obtained relating the electric currents needed on the magnetic lenses for an optimal ion beam focus and the beam energy. The irradiation process with ion beam proved itself efficient for the production of regular patterns on PET foils. The optimum dose of prótons to be used on the patterning processes was estimated in 6 x 1014 ions/cm2. For this dose, etching times smaller than 1 minute were enough to remove all the irradiated area. However, times slightly longer (e.g. 2 minutes) make the process more reproducible. Regarding the geometry of the patterns generated by the ion irradiation, asymmetries were observed on structures that were supposed to be symmetric. This problem was attributed to the asymmetry of the beam spot on the target due to the settings of the objective slits that collimates the beam. The study of the grafting process showed that the hydrogel adheres to the structures walls, but does not fill it. For high concentrations (e.g. 0,7 g/L), the process is not efficient, since no reduction of the area of the microstructures by the insertion of the hydrogel was observed. The electric measurements showed the existence of distinct regimes as a function of the frequency of the alternate current. Basically, the polymer foils present resistive and capacitive behaviors.
26

Characterisation of store-operated calcium entry in a vascular endothelial cell line and impact on the production of nitric oxide

Batchelor, Helen R. January 2014 (has links)
Store-operated calcium entry (SOCE) is a principal mechanism for extracellular calcium entry in non-excitable cell types, and is primarily facilitated by the calcium- release activated calcium (CRAC) channel; itself comprised of the pore-forming Orai-1 and calcium-sensing Stromal interaction molecule (STIM)-1 proteins. Depletion of endoplasmic reticulum (ER) calcium stores initiates STIM-1 translocation to defined ER-plasma membrane puncta, and subsequent Orai-STIM interaction and opening of Orai. The importance of this mechanism in calcium signalling in diverse tissue types is becoming increasingly clear. The vascular endothelium is a dynamic tissue, involved in the maintenance of vascular homeostasis and haemostasis. Many endothelium-derived bioactive agents, such as endothelin-1, prostaglandins, and the potent vasodilator nitric oxide (NO), are known to be produced via calcium- dependent mechanisms. However, the role of the CRAC channel in the vascular endothelium is poorly defined with little known about downstream targets of calcium influx through CRAC channels. The dysregulation of NO production by endothelial nitric oxide synthase (eNOS) is a major contributory factor in many vascular disease states, yet the calcium channel responsible for eNOS activation has yet to be identified. Within this thesis, I establish the endothelial cell line sEnd.1 as a new model system for studying CRAC channel signalling in the vascular endothelium, defining sEnd.1 SOCE as being CRAC channel-dependent. Inhibition of CRAC channels with an array of inhibitors, and knock-down of STIM-1, both reduced ATP- and TG-induced SOCE. The sEnd.1 model system was subsequently used to identify calcium entry through the CRAC channel as the elusive activation mechanism for eNOS. Through real-time imaging with the fluorescent NO dye DAF-2-DA, we established that NO production is non-linear, with a slow initial increase preceding a faster NO production phase. These kinetics, with a characteristic delay before fast production have, to our knowledge, not previously been reported. The time taken to reach the fast phase of NO production could be manipulated through changes in both local and bulk calcium rises, which indicated roles for both elements of calcium signalling in eNOS activation. eNOS regulation by calcium is complex, occurring not only through direct binding of calcium-calmodulin, but additionally through changing post-translational modifications, which in turn regulate the calcium-dependency of eNOS, such as phosphorylation of Ser1177. We propose that the delay in fast production of NO is due to the time taken to alter eNOS post-translational modifications, which thus remove inhibition on eNOS. Activation of CRAC channels increased phosphorylation of residue Ser1177 via calcium-calmodulin kinase II (CaMKII), with a similar time course to that required to reach the fast phase of NO production. Inhibition of CaMKII increased the time taken to reach fast activation. In conclusion this thesis presents a new model system for investigation of CRAC channel signalling in the endothelium. Furthermore, we clearly identify a critical endothelial pathway as being regulated by CRAC channels, by demonstrating the production of NO in response to both ATP and TG, which stimulate calcium entry through CRAC channels.
27

Microestruturação de membranas de poli (tereftalato de etileno) por microfeixe de íons

Souza, Cláudia Telles de January 2013 (has links)
Neste trabalho, o processo de estruturação por microfeixe de íons foi utilizado para a produção de membranas microporosas em folhas comerciais de PET. O processo de estruturação por microfeixe de íons consiste basicamente na interação direta entre um feixe de íons de dimensões micrométricas com o material em questão. As zonas modificadas pelo feixe são removidas do restante do material através de um processo químico. Nesse contexto, durante o desenvolvimento deste trabalho, sistemáticas experimentais para o processo de estruturação foram desenvolvidas. Com o intuito de operacionalizar a linha de microfeixe presente no Laboratório de Implantação Iônica da UFRGS, foi necessário realizar um estudo aprofundado sobre o funcionamento de todo o sistema, verificando problemas e explorando a potencialidade de técnicas não convencionais de análise de materiais. O estudo sobre a sistemática de estruturação ocorreu através da investigação de parâmetros clássicos, como fluência utilizada durante a irradiação e tempo de ataque químico. Para atingir tais objetivos, amostras de poli (tereftalato de etileno) (Mylar) de 12 μm foram irradiadas com microfeixe de íons (H+ e He++) com energias de 3 e 2,2 MeV e fluências que variaram entre 1 x 1011 e 6 x 1015 íons/cm2. Posteriormente à irradiação, as amostras foram submetidas a um ataque químico com solução alcalina de hidróxido de sódio 6 M durante tempos que variaram de 0,5 à 60 minutos. A temperatura do ataque em todos os casos se manteve fixa em 60°C. A caracterização das amostras foi realizada através de microscopia eletrônica de varredura (MEV) e por microscopia de transmissão iônica (STIM). As amostras também foram caracterizadas através de medidas elétricas utilizando um circuito de corrente alternada. O processo de enxertia (grafting) foi testado nas membranas estruturadas, utilizando um hidrogel de PNIPAAm com concentrações de 0,340, 0,450 e 0,700 g/L. Tais resultados também foram analisados através de MEV. O estudo sobre a linha de microfeixe permitiu verificar a existência de problemas relacionados ao registro da carga elétrica durante as irradiações. Além disso, para o ajuste do foco do feixe de íons, foram feitas curvas de calibração de corrente para as lentes magnéticas considerando diferentes energias de feixe. O processo de estruturação através da técnica de microfeixe de íons se mostrou eficaz para a produção de estruturas regulares e definidas em folhas de PET. A fluência ótima de prótons a ser utilizada nos processos de estruturação foi estimada em 6 x 1014 íons/cm2. Para esta fluência, tempos de ataque químico inferiores a 1 minuto já são suficientes para corroer toda a parte irradiada. Entretanto, tempos um pouco mais longos (e.g. 2 minutos) tornam o processo mais reprodutível. Com relação à geometria das estruturas fabricadas, observou-se irregularidades em estruturas que, em princípio, deveriam ser simétricas. Esse problema foi atribuído à assimetria do feixe, proveniente de ajustes dos parâmetros de colimação do feixe. Finalmente, o estudo do processo de enxertia mostrou que o hidrogel adere nas paredes das estruturas, porém não as preenche. Para concentrações elevadas (e.g. 0,7 g/L) o processo não é tão eficiente, sendo que não é verificada a redução da área das microestruturas pela inserção do hidrogel. As medidas elétricas mostraram a existência de regimes distintos e dependentes da frequência da corrente alternada. Os polímeros apresentaram basicamente comportamentos resistivo e capacitivo. / In this work, the process of irradiation of PET foils with ion beams in the micrometer size range was used for the production of microporous membranes. Basically, this process consists on the direct interaction between the ion beam and the material under study. The regions modified by the beam are removed from the material through a chemical process. In this context, experimental procedures for the production process of the membranes were developed during the course of this work. In order to make the microbeam station of the Ion Implantation Laboratory of the Federal University of Rio Grande do Sul (UFRGS), it was necessary to perform a thorough study of the operational parameters of the system, thus allowing a proper identification of problems and providing grounds for pushing the technique to the frontier of materials science. To achieve such objectives, foils of polyethylene terephtalate (Mylar®) 12 μm thick were irradiated with H+ and He++ ions with 3 e 2,2 MeV respectively. Fluencies varied from 1 x 1011 and 6 x 1015 ions/cm2. After the irradiation, the foils were submitted to an etching procedure using alkaline solution of sodium hydroxide at 6 M during periods of time varying from 0,5 to 60 minutes. In all cases, the temperature of the etching was fixed at 60°C. The characterization of the samples was performed through scanning electron microscopy (SEM) and scanning transmission ion microscopy (STIM). The samples also were characterized by electric measurements using an AC current circuit. The process of grafting was tested on the structured membranes using a PNIPAAm hydrogel with concentrations of 0,340, 0,450 and 0,700 g/L. The results of this study were also analyzed through MEV. With the present study, it was possible to pinpoint problems related to the integration and recording of the charge during the irradiations. Besides that, calibration curves were obtained relating the electric currents needed on the magnetic lenses for an optimal ion beam focus and the beam energy. The irradiation process with ion beam proved itself efficient for the production of regular patterns on PET foils. The optimum dose of prótons to be used on the patterning processes was estimated in 6 x 1014 ions/cm2. For this dose, etching times smaller than 1 minute were enough to remove all the irradiated area. However, times slightly longer (e.g. 2 minutes) make the process more reproducible. Regarding the geometry of the patterns generated by the ion irradiation, asymmetries were observed on structures that were supposed to be symmetric. This problem was attributed to the asymmetry of the beam spot on the target due to the settings of the objective slits that collimates the beam. The study of the grafting process showed that the hydrogel adheres to the structures walls, but does not fill it. For high concentrations (e.g. 0,7 g/L), the process is not efficient, since no reduction of the area of the microstructures by the insertion of the hydrogel was observed. The electric measurements showed the existence of distinct regimes as a function of the frequency of the alternate current. Basically, the polymer foils present resistive and capacitive behaviors.
28

Utilização de técnicas de microfeixe de íons energéticos para caracterização morfológica e elementar de amostras poliméricas e tecidos biológicos

Stori, Elis Moura January 2014 (has links)
As técnicas baseadas em microfeixe de íons energéticos possuem aplicações em diferentes áreas de conhecimento, tais como materiais, biologia, neurociência, ciências ambientais, entre outros. A microssonda iônica também possui a capacidade de fabricar micro-estruturas com aplicações em biomateriais, micro-fotônica, micro-fluídica, membranas porosas e diversas outras. O Laboratório de Implantação Iônica do Instituto de Física (LII) da UFRGS (Universidade Federal do Rio Grande do Sul) conta com uma linha de microssonda iônica que dispõe de detectores para a realização de diversos tipos de experimentos: Emissão de RaiosX Induzida por Partículas (Particle Induced X-Ray Emission – PIXE), Espectroscopia de Espalhamento de Rutherford (Rutherford Backskattering Spectroscopy – RBS), Reação Nuclear (Nuclear Reaction Analysis – NRA) e Microscopia Iônica de Varredura por Transmissão (Scanning Transmission Ion Microscopy – STIM). Além disso, tem-se aperfeiçoado a técnica de micro-fabricação denominada Litografia por Feixe de Prótons (Proton Beam Writing – PBW), atualmente em substratos poliméricos. Este trabalho apresenta dois focos: um deles é a análise de fígado de peixe pela técnica de micro-PIXE. Estes fígados apresentam lesões associadas à exposição de contaminantes. Essas lesões são acompanhadas de células pigmentosas à base de metais chamadas de centros de melanomacrófagos. Observou-se que o fígado de peixe é uma amostra em potencial para estudos ambientais. Outro foco foi o estudo da técnica de STIM em películas poliméricas micro-fabricadas por PBW. Foram estudadas diferentes configurações geométricas para a técnica de STIM, bem como a utilização de feixes de H+1, He+2 e Li+3. Diferentes amostras foram preparadas, desde estruturas simples (possuindo apenas orifícios) até amostras multi-estruturadas do tipo degrau. As medidas de STIM foram comparadas com medidas de Microscopia Eletrônica de Varredura (MEV) de maneira a confirmar a viabilidade e confiabilidade dos estudos morfológicos das amostras em questão. A técnica de STIM se apresentou viável para o estudo morfológico de microestruturas fabricadas por microfeixe de íons em películas poliméricas, sendo que a melhor configuração é na geometria on-axis utilizando o íon He+2 que provê melhor resolução em energia, sem comprometer a resolução espacial. Em comparação com medidas de MEV, apresenta vantagens como maior rapidez, preservação da amostra e o poder de resolver estruturas enterradas na amostra. A similaridade entre as duas técnicas com relação às demais características faz do STIM uma excelente alternativa à mais comumente utilizada para diversas análises morfológicas de películas poliméricas. / Ion beam techniques have many applications in different areas such as materials, biology, neuroscience and environmental science among others. The ion microprobe has also the ability of fabricating microstructures with applications in the fields of biomaterials, micro-photonics, micro-fluidics, porous membranes and many others. The Ion Implantation Laboratory of the Physics Institute at UFRGS has a microprobe beamline equiped with detectors used in different techniques: Particle Induced X-Ray Emission (PIXE), Rutherford Backscattering Spectroscopy (RBS), Nuclear Reaction Analysis (NRA) and Scanning Transmission Ion Microscopy (STIM). Besides, its scanning capability makes allows the use of the micro-fabrication technique called Proton Beam Writing (PBW). Currently, this technique has been used to write micro-structures over polymers. Several projects are in progress for the development and improvement of such techniques, since the microbeam line is a recent acquisition by the laboratory. This work presents two guidelines: one of them is the analysis of fish liver through the micro-PIXE technique. These livers present injuries associated to the exposure of contaminants. The injuries are characterized by the presence of pigmented cells based on metals called melanomacrophage centers. It was observed that the fish liver is a promising sample for environmental studies. The other guideline is the study of the STIM technique on micro-fabricated polymer foils by PBW. Different geometric configurations for the STIM technique were explored, as well as the use of different ion beams (H+1, He+2 and Li+3). Different samples were prepared, ranging from simple structures (containing only one hole) to step-like multi-structured samples. STIM measurements were compared with Scanning Electron Microscopy (SEM) in order to confirm the viability and reliability of morphological studies of the samples under study. The STIM technique proved to be suitable for the morphological study of micro-structures fabricated by ion microbeam on polymeric foils. The best configuration is the on-axis geometry using He+2 beam, which provides the best energy resolution without compromising the spatial resolution. In comparison with SEM measurements, advantages such as speed of measurement, non-destructiveness and power of resolving buried structures of the sample were observed. Concerning other features, the similarities between the two techniques make STIM an excellent alternative for morphological analysis of polymeric foils.
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Implementação de um nó IEEE 1451, baseado em ferramentas abertas e padronizadas, para aplicações em ambientes de instrumentação distribuída

Rossi, Silvano Renato [UNESP] 14 January 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-01-14Bitstream added on 2014-06-13T18:42:30Z : No. of bitstreams: 1 rossi_sr_dr_ilha.pdf: 2325960 bytes, checksum: 7ef7ad22ede243a4f480a84cc0e63023 (MD5) / Universidad Nacional de Asuncion / Atualmente, as redes de transdutores inteligentes desempenham um papel de importância vital em sistemas de Medição e Controle Distribuído. Nesse contexto, o Padrão IEEE 1451 para interfaceamento de transdutores inteligentes tem como objetivo simplificar a conectividade de transdutores em ambientes de rede, fornecendo, para tal fim, um conjunto de interfaces padronizadas, aumentando a flexibilidade dos sistemas de instrumentação distribuída. Neste trabalho descreve-se a implementação de um nó de rede em conformidade com o padrão IEEE 1451. O nó foi completamente desenvolvido através do emprego de ferramentas padronizadas e sistemas abertos. O nó é composto por um Processador de Aplicação com Capacidade de Operar em Rede (NCAP), com base no padrão IEEE 1451.1 e um Módulo de Interface para Transdutores Inteligentes (STIM), em conformidade com o padrão IEEE 1451.2. A parte física do NCAP foi implementada através dos recursos de um Computador Pessoal (PC) e de um Dispositivo Lógico Programável (PLD) de uso geral. A parte lógica do NCAP foi desenvolvida através da tecnologia Java. O STIM foi implementado com dispositivos lógicos programáveis versáteis, de uso geral, e sua funcionalidade foi integralmente descrita em linguagem de descrição de hardware. O conjunto NCAP-STIM foi conectado a uma rede de área local, sob o modelo de comunicação cliente-servidor, sendo que várias aplicações clientes podem acessar as informações dos transdutores conectados ao STIM, através da rede, via intermediação do NCAP. O emprego de ferramentas padronizadas e abertas no desenvolvimento total do sistema IEEE 1451 é uma das contribuições mais importantes do presente trabalho. No entanto, há várias contribuições pontuais como: a maneira de descrever as Informações de Transdutores em Formato Eletrônico (TEDS), a implementação... . / Nowadays, smart transducer networks play an essential role in distributed measurement and control systems. In this context, the IEEE 1451 smart transducer interface standards aimed to simplify transducer connectivity, providing a set of common interfaces for connecting transducers in a networked fashion, increasing the flexibility of distributed instrumentation systems. In this work the implementation of a network node according to the IEEE 1451 standard is introduced. The node has been fully developed using open and standardized tools. A Network Capable Application Processor (NCAP) according to the IEEE 1451.1 Standard and a Smart Transducer Interface Module (STIM) comprises the node. The physical part of the NCAP has been implemented using the resources of a Personal Computer (PC) and a general-purpose Programmable Logic Device (PLD). The logical part of the NCAP has been developed using Java technology. The STIM module was implemented with versatile, general-purpose Programmable Logic Devices. STIM functionality has been fully developed in hardware description language. A network node (STIM-NCAP) was connected in a client-server modelbased local area network. Many client applications can access STIM transducers information, through the network with the NCAP as an intermediary. One of the most important contributions of this work is the employment of open and standardized tools for implementing the IEEE 1451 network node. However, there are many specific contributions such as: Transducer Electronic Data Sheet (TEDS’s) description method, programmable logic-based Protocol Manager implementation that allows the use of the parallel port without any modification, the employment of low-cost PLDs for implementing the STIM and the Protocol Manager, and Java-based NCAP software development. Through the implementation of the IEEE Standard, industries... (Complete abstract, click electronic address below).
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MATIUDE - monitoramento e acesso a transdutores inteligentes (Padrão IEEE 1451) utilizando dispositivos embarcados (celulares e PDA's) /

Santos Filho, Tércio Alberto dos. January 2007 (has links)
Resumo: Neste trabalho foi desenvolvido um aplicativo para os dispositivos móveis (celulares e PDA's) chamado MATIUDE (Monitoramento e Acesso aos Transdutores Inteligentes Utilizando os Dispositivos Embarcados) para o monitoramento e acesso aos transdutores inteligentes em conformidade com o padrão IEEE 1451. O sistema realiza a comunicação com o NCAP utilizando a rede ethernet. A comunicação entre o NCAP com os módulos inteligentes é realizada por meio da interface física padronizada TII podendo acoplar num total de 255 transdutores por módulo STIM. Os testes foram realizados em um sistema de distribuição de água no laboratório Hidrologia e Hidrometria, na maquete de uma granja e no monitoramento de temperatura ambiente, porém desenvolvidos no Laboratório de Processamento de Sinais e Sistemas Digitais. Os resultados obtidos comprovam o bom funcionamento do sistema. / Abstract: On this work, an applicatory for mobile devices (cellular and PDA's) called MATIUDE (Monitoring and Access to the Smart Transducers Using the Embedded Devices) was developed for monitoring and access to the smart transducers in compliance with the standard IEEE 1451. The communication between the NCAP and the smart modules is performed though the physical interface standardized TII limiting the system in a total of 255 transducers per module STIM. The tests were carried in a water distribution system in the Hydrology and Hydrometric laboratory on a mockup's farm and ambient temperature monitoring, both developed in the Signal Processing and Digital System Laboratory. The results prove the good working. / Orientador: Alexandre César Rodrigues da Silva / Coorientador: Aparecido Augusto de Carvalho / Banca: Carlos Antonio Alves / Banca: Mauro Conti Pereira / Mestre

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