This dissertation focuses on the design, synthesis, characterization of platinum (II) pyridylazolate complexes and develop high performance organic light emitting diodes (OLEDs) and design and execute high-sensitivity humidity sensors based on the luminescent metal-organic complexes of platinum. A majority of existing platinum compounds do not dissolve in organic solvents, making it difficult to analyze the photophysical characteristics of complexes in solution, a key part of understanding chemical photophysical properties. Furthermore, due to the poor quantum yield, it is inefficient for use in devices such as OLEDs. Chapter 2 reports the synthesis and characterization of a novel heteroleptic platinum(II) pyridylazolate complex with high solubility and quantum yield. The photochemistry of the complex is studied, including efficiency, emission profiles, and lifetimes at different temperatures. Chapter 3 reports the power efficiency (lm/W), current efficiency (cd/A), external quantum efficiency (EQE), luminance and operating voltage (V) of OLED devices made with the heteroleptic platinum(II) pyridylazolate complex. The relation between thickness of hole transport layer and electron transport layer on performance of devices has been studied through building a variety of devices. Chapter 4 includes application of a homoleptic platinum(II) pyridylazolate complex in humidity sensor. In many environments, the relationship between moisture content and emissive wavelength has been investigated. This research reveals that regardless of the humidity level, there is a link between increasing the temperature and decreasing the moisture absorption capacity of the complex.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Este trabalho teve como objetivos montar e instalar sistemas de irrigaÃÃo com diferentes nÃveis de automaÃÃo: automÃtico inteligente, automÃtico por temporizador e nÃo automÃtico. Foi conduzido um experimento na Ãrea experimental do LaboratÃrio de HidrÃulica e IrrigaÃÃo da Universidade Federal do CearÃ, em Fortaleza, CE, no perÃodo de outubro de 2004 a janeiro de 2005. Esses trÃs sistemas foram distribuÃdos em um delineamento estatÃstico em blocos casualizados. O delineamento constou de 6 blocos e trÃs tratamentos distribuÃdos em 18 parcelas experimentais medindo 4m de largura e 12m de comprimento, ocupando uma Ãrea total de 1600m2. A montagem foi dividida em duas fases, a primeira fase consistiu na montagem dos sistemas eletrÃnico e elÃtrico composto por sensores de umidade (blocos de resistÃncia), sensores de temperatura (termopares), datalogger, multiplexador, placa digital de E/S padrÃo ISA, placa condicionadora de relÃs, temporizador, contactores, relÃs, chave de partida, cabeamento, aterramento e a segunda dos sistemas hidrÃulico e de irrigaÃÃo composto de bombas, tubulaÃÃes, reservatÃrios, manÃmetros, hidrÃmetros, venturis, tomadas de pressÃo e conexÃes; todos os sistemas preconizados foram montados e instalado no campo. / This work had as objectives to set up and to install overhead irrigations with different automation levels: automatic intelligent, automatic for temporizador and no automatic. An experiment was driven in the experimental area of the Laboratory of Hydraulics and Irrigation of the Federal University of CearÃ, in Fortaleza, CE, in the period of October of 2004 to January of 2005. Those three systems were distributed in a statistical delineamento in blocks casualizados. The delineamento consisted of 6 blocks and three treatments distributed in 18 experimental portions measuring 4m of width and 12m of length, occupying a total area of 1600m2. The assembly was divided in two phases, the first phase consisted of the assembly of the electronic and electric systems composed for sensor of humidity (resistance blocks), sensor of temperature (termopares), datalogger, multiplexador, digital plate of E/S pattern ISA, conditioning plate of relÃs, temporizador, contactores, relÃs, departure key, cabeamento, aterramento and Monday of the waterworks and of irrigation composed of bombs, piping, reservoirs, manÃmetros, hydrometers, venturis, pressure sockets and connections; all of the extolled systems were mounted and installed in the field.

MACIEL, Wlisses Matos. Montagem e instalação de um sistema de controle automático de irrigação. 2005. 85 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2005. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-28T19:28:16Z No. of bitstreams: 1 2005_dis_wmmaciel.pdf: 1582032 bytes, checksum: 45d12f1338751fa3fbd6a49b302faf2c (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-06-30T22:48:21Z (GMT) No. of bitstreams: 1 2005_dis_wmmaciel.pdf: 1582032 bytes, checksum: 45d12f1338751fa3fbd6a49b302faf2c (MD5) / Made available in DSpace on 2016-06-30T22:48:21Z (GMT). No. of bitstreams: 1 2005_dis_wmmaciel.pdf: 1582032 bytes, checksum: 45d12f1338751fa3fbd6a49b302faf2c (MD5) Previous issue date: 2005 / This work had as objectives to set up and to install overhead irrigations with different automation levels: automatic intelligent, automatic for temporizador and no automatic. An experiment was driven in the experimental area of the Laboratory of Hydraulics and Irrigation of the Federal University of Ceará, in Fortaleza, CE, in the period of October of 2004 to January of 2005. Those three systems were distributed in a statistical delineamento in blocks casualizados. The delineamento consisted of 6 blocks and three treatments distributed in 18 experimental portions measuring 4m of width and 12m of length, occupying a total area of 1600m2. The assembly was divided in two phases, the first phase consisted of the assembly of the electronic and electric systems composed for sensor of humidity (resistance blocks), sensor of temperature (termopares), datalogger, multiplexador, digital plate of E/S pattern ISA, conditioning plate of relés, temporizador, contactores, relés, departure key, cabeamento, aterramento and Monday of the waterworks and of irrigation composed of bombs, piping, reservoirs, manômetros, hydrometers, venturis, pressure sockets and connections; all of the extolled systems were mounted and installed in the field. / Este trabalho teve como objetivos montar e instalar sistemas de irrigação com diferentes níveis de automação: automático inteligente, automático por temporizador e não automático. Foi conduzido um experimento na área experimental do Laboratório de Hidráulica e Irrigação da Universidade Federal do Ceará, em Fortaleza, CE, no período de outubro de 2004 a janeiro de 2005. Esses três sistemas foram distribuídos em um delineamento estatístico em blocos casualizados. O delineamento constou de 6 blocos e três tratamentos distribuídos em 18 parcelas experimentais medindo 4m de largura e 12m de comprimento, ocupando uma área total de 1600m2. A montagem foi dividida em duas fases, a primeira fase consistiu na montagem dos sistemas eletrônico e elétrico composto por sensores de umidade (blocos de resistência), sensores de temperatura (termopares), datalogger, multiplexador, placa digital de E/S padrão ISA, placa condicionadora de relés, temporizador, contactores, relés, chave de partida, cabeamento, aterramento e a segunda dos sistemas hidráulico e de irrigação composto de bombas, tubulações, reservatórios, manômetros, hidrômetros, venturis, tomadas de pressão e conexões; todos os sistemas preconizados foram montados e instalado no campo.

Thin film material properties and measurement characterisation techniques are crucial for the development of micro-electromechanical systems (MEMS) devices. Furthermore, as the technology scales down from microtechnology towards nanotechnology, nanoscale materials such as carbon nanotubes (CNTs) are required in electronic devices to overcome the limitations encountered by conventional materials at the nanoscale. The integration of CNTs into micro-electronics and material applications is expected to provide a wide range of new applications. The work presented in this thesis has contributed to the development of thin film material characterisation through research on the thermal conductivity measurement and the control of the residual stress of thin film materials used commonly in MEMS devices. In addition, the use of CNTs in micro-electronics and as filler reinforcement in composite materials applications have been investigated, leading to low resistivity CNTs interconnects and CNTs-Polyimide (PI) composites based resistive humidity sensors. In the first part of this thesis, the thermal conductivity of conductive thin films as well as the control of the residual stress arising from fabrication process in PI micro-cantilevers have been studied. A MEMS device has been developed for the thermal conductivity characterisation of conductive thin films showing good agreement with thermal conductivity of bulk material. Low energy Ar+ ion bombardment in a plasma has been used to control the residual stress present in PI cantilevers. Appropriate ion energy and exposure time have led to stress relaxation of the beams resulting in a straight PI cantilever beam. In the second part of this thesis, low resistivity CNTs interconnects have been developed using both dielectrophoresis (DEP) and Focused Ion Beam (FIB) techniques. An investigation of the effects of CNT concentration, applied voltage and frequency on the CNTs alignment between Al and Ti electrodes has resulted in the lowering of the CNTs’ resistance. The deposition of Pt contact using FIB at the CNTs-metal electrodes interface has been found to decrease the high contact resistances of the devices by four and two orders of magnitude for Al and Ti electrodes respectively. The last part of this thesis focuses on the preparation of CNTs-PI composite materials, its characterisation and its application as resistive humidity sensor. The integration of CNTs inside the PI matrix has resulted in enhancing significantly the electrical and mechanical properties of the composites. In particular, a DEP technique employed to induce CNTs alignment inside the PI matrix during curing has been attributed to play an important role in improving the composite properties and lowering the percolation threshold. In addition, the fabrication and testing of CNTs-PI resistive humidity sensors have been carried out. The sensing performance of the devices have shown to be dependent highly on the CNT concentration. Finally, the alignment of CNTs by DEP has improved the sensing properties of CNTs-PI humidity sensors and confirmed that the change of resistance in response to humidity is governed by the change of the CNTs’ resistances due to charge transfer from the water molecules to the CNTs.

<p>Detection and control of humidity is very important in our everyday life.<br />Humidity sensors are used in many areas, such as meteorology,<br />environmental protection, medicine, food industry, agriculture, etc.<br />Various transduction techniques, such as capacitive, resistive, acoustic,<br />optical and mechanical, have been adopted for the design of humidity<br />sensors.In the last two decades, carbon nanomaterials materials,<br />especially graphene, are taking their place in the production of humidity<br />sensors. In addition to graphene, graphene oxide (Graphene-oxide-GO)<br />is involved in many areas from electronics to sensors. Printed electronics<br />increasingly becomes the leading technology in the fabrication of<br />sensors. In addition to inexpensive manufacturing and additive processes<br />with reduced infrastructure, the benefits of printed technology are lowpower<br />components, flexible, transparent, thin, components that can be<br />embedded in/on clothes, as well as the production of a large number of<br />components. In the last few years, robots are more involved in human&rsquo;s<br />life, which has led to the need for advanced research in the field of<br />robotics. People communicate with the environment using four senses:<br />touch, hearing, sight and taste. The sense of touch allows people to grab<br />various objects, lift them, perform various tasks, etc. For this reason, it is<br />very important to develop touch sensors, that is, the sensors that will be<br />incorporated into robotic fingers. As one type of such sensor, Force<br />Sensing Resistors (FSR) are used. In these sensors, there is a change in<br />resistance if the sensor is affected by a certain force.</p> / <p>Детекција и контрола влажности су од суштинског значаја у нашем<br />свакодневном животу. Сензори влаге се користе у многим областима,<br />као што су метеорологија, заштита животне средине, медицина,<br />прехрамбена индустрија, пољопривреда, итд. За дизајн сензора влаге<br />углавном се користе капацитивне, резистивне, акустичне, механичке<br />или оптичке структуре. У посљедње двије деценије све више се користе<br />наноструктурни угљенични материјали, посебно графен. Поред графена<br />велику пажњу у многим областима од електронике до сензора је<br />привукао графен-оксид (Graphene-oxide - GO). Штампана електроника<br />све више постаје водећа технологија у изради сензора. Поред јефтине<br />израде и адитивних процеса са смањеном инфраструктуром, предности<br />штампане технологије су компоненте мале масе, савитљиве,<br />транспарентне, танке, компоненте које се могу уградити у/на гардеробу<br />и носити, као и производња великог броја компоненти. У последњих<br />неколико година роботи се све више укључују у људски живот, што је<br />довело до потребе за усавршавањем у области роботике. Људи са<br />окружењем комуницирају помоћу четири чула: додира, слуха, вида и<br />укуса. Чуло додира људима омогућава да дохвате различите предмете,<br />подигну их, обављају различите задатке, итд. Из тог разлога је развој<br />сензора додира, односно сензора који би се уградили у роботске прсте,<br />од веома великог значаја. Као једна врста таквих сензора су отпорнички<br />сензори силе (Force Sensing Resistors - FSR). Код ових сензора долази<br />до промјене отпорности уколико се на сенсор дјелује одређеном силом.</p> / <p>Detekcija i kontrola vlažnosti su od suštinskog značaja u našem<br />svakodnevnom životu. Senzori vlage se koriste u mnogim oblastima,<br />kao što su meteorologija, zaštita životne sredine, medicina,<br />prehrambena industrija, poljoprivreda, itd. Za dizajn senzora vlage<br />uglavnom se koriste kapacitivne, rezistivne, akustične, mehaničke<br />ili optičke strukture. U posljednje dvije decenije sve više se koriste<br />nanostrukturni ugljenični materijali, posebno grafen. Pored grafena<br />veliku pažnju u mnogim oblastima od elektronike do senzora je<br />privukao grafen-oksid (Graphene-oxide - GO). Štampana elektronika<br />sve više postaje vodeća tehnologija u izradi senzora. Pored jeftine<br />izrade i aditivnih procesa sa smanjenom infrastrukturom, prednosti<br />štampane tehnologije su komponente male mase, savitljive,<br />transparentne, tanke, komponente koje se mogu ugraditi u/na garderobu<br />i nositi, kao i proizvodnja velikog broja komponenti. U poslednjih<br />nekoliko godina roboti se sve više uključuju u ljudski život, što je<br />dovelo do potrebe za usavršavanjem u oblasti robotike. LJudi sa<br />okruženjem komuniciraju pomoću četiri čula: dodira, sluha, vida i<br />ukusa. Čulo dodira ljudima omogućava da dohvate različite predmete,<br />podignu ih, obavljaju različite zadatke, itd. Iz tog razloga je razvoj<br />senzora dodira, odnosno senzora koji bi se ugradili u robotske prste,<br />od veoma velikog značaja. Kao jedna vrsta takvih senzora su otpornički<br />senzori sile (Force Sensing Resistors - FSR). Kod ovih senzora dolazi<br />do promjene otpornosti ukoliko se na sensor djeluje određenom silom.</p>

Cette thèse explore l’utilisation des principes de la chimie supramoléculaire afin de fabriquer des dispositifs senseurs de gaz novateurs et à haute performance, avec une lecture (opto)-électronique. Parmi les différentes sections, divers échafaudages tels que des réseaux hybrides bi- et tridimensionnels de particules d’or et des nanofibres supramoléculaires sont utilisés comme matériaux actifs pour la détection quantitative de l’humidité. Au sein de la dernière section, des couches 2D d’oxyde de graphène sont fabriquées par exposition à un laser IR, puis comme validation de principe, exploitées comme matériau actif pour la détection d’ozone à une concentration ppm. Chacun des échafauds présentés est basé sur un mécanisme de transduction différent, mais dans tous les cas, les interactions entre récepteurs et analytes sont basés sur des liaisons dynamiques non covalentes. / This thesis explores the use of supramolecular chemistry principles to fabricate novel and high performances gas sensing devices, featuring (opto)-electronic readouts. Within the different sections, diverse scaffolds such as 2D and 3D hybrid networks of gold nanoparticles and 1D supramolecular nanofibers are exploited as active materials for the quantitative detection of environmental humidity. In the last section, 2D layers of reduced graphene oxide are fabricated by IR laser exposure and, as a proof-of-concept application, they are exploited as active materials for the detection of ozone in ppm concentration. Each of the presented scaffolds rely on a different transduction mechanism but, in all the cases, the interactions between the receptors and the analytes are based on dynamic non-covalent bonds.

No description available.

Studien gick ut på att undersöka och ta fram relativa luftfuktighetsgivare som ger godkända mätvärden mellan [5%, 95%] relativ luftfuktighet med klimatkammare som referens. Med syftet att ersätta företagets givare i deras NDIR koldioxidsensor. Den skulle ersättas då deras nuvarande luftfuktighetsgivare gav felaktiga värden när klimatet gick mot antingen väldigt torrt eller fuktigt. Det är väsentligt att luftfuktighetsgivaren fungerar eftersom företaget använder värdena från givaren för att ge korrekta koldioxidmätningar i deras NDIR sensor. Detta är möjligt eftersom koldioxidhalter har visats sig påverkas av den relativa luftfuktigheten. Givarna införskaffades och monterades på PCB’s. Kod utvecklades för insamling av data genom I2C och SPI kommunikation. Givarna kördes sedan i en klimatkammare som svepte luftfuktigheten mellan [5%, 95%]. Värdena illustrerades i Matlab genom grafer. Givare 2 visade sig ge bäst värden på hela spannet jämfört med resterande givare. Den hade absolut minst avvikelse vid extrempunkterna, samt låg nära referensvärdet vid resterande luftfuktigheter i svepet [5%, 95%]. / The purpose of the study was to examine and bring forth a relative humidity sensor which gives approved values for the span between [5%, 95%] relative humidity with the climate chamber as the reference point. The goal was to replace the companies relative humdity sensor in their NDIR carbon dioxide sensor. It was to be replaced because their current sensor gave incorrect values when the climate was really humid or dry. It’s of value that the sensor gives correct values because the company uses relative humdity readings to correct their carbon dioxide reading in their NDIR sensor. The reason this works is because the carbon dioxide levels has been showed to correlate with the relative humidity. The sensors were studied and bought. They were mounted on top of PCB’s. Code was developed to gather data from I2C and SPI communication. The sensors was then put into an climate chamber and got swept between [5%,95%] relative humidity. The values were illustrated in Matlab through graphs. Sensor 2 proved to give the best values on the entire span [5%, 95%] relative humidity in comparison to the other sensors in the study. It had the least added error of all the sensors at dry/humid climates and was really close to the reference value at the other points of span [5%, 95%] relative humidity.

This work is part of the inter-laboratory collaboration to study the stability of seven distinct sets of state-of-the-art organic photovoltaic (OPV) devices prepared by leading research laboratories. All devices have been shipped to and degraded at RISØ-DTU up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. In this work, we apply the Incident Photon-to-Electron Conversion Efficiency (IPCE) and the in situ IPCE techniques to determine the relation between solar cell performance and solar cell stability. Different ageing conditions were considered: accelerated full sun simulation, low level indoor fluorescent lighting and dark storage. The devices were also monitored under conditions of ambient and inert (N2) atmospheres, which allows for the identification of the solar cell materials more susceptible to degradation by ambient air (oxygen and moisture). The different OPVs configurations permitted the study of the intrinsic stability of the devices depending on: two different ITO-replacement alternatives, two different hole extraction layers (PEDOT:PSS and MoO3), and two different P3HT-based polymers. The response of un-encapsulated devices to ambient atmosphere offered insight into the importance of moisture in solar cell performance. Our results demonstrate that the IPCE and the in situ IPCE techniques are valuable analytical methods to understand device degradation and solar cell lifetime. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Ce travail nous a permis de réaliser une étude de capteurs de gaz et d’humidité à base de graphène. Cette étude pourrait être utile non seulement pour améliorer les performances des capteurs à base de graphène mais aussi pour mieux comprendre l’interaction entre le graphène et les molécules de gaz. Ceci semble indispensable pour faire avancer les applications du graphène comme un matériau prometteur pour la détection des gaz. Des avancées significatives ont été présentées au niveau de la fabrication de ces capteurs, leurs différentes caractérisations électriques ainsi que d’autres techniques employées pour analyser le mécanisme contrôlant la détection des molécules de gaz/vapeur. Ces outils ont été mis en place pour concevoir et fabriquer plusieurs structures de capteur en utilisant différents substrats support du graphène d’une part et en modifiant les propriétés du graphène par utilisation des produits chimiques d’autres part. La caractérisation de ces capteurs sous différents environnements a permis de comparer les différentes réponses des capteurs et d’en tirer plusieurs conclusions sur le fonctionnement de ces dispositifs. En effet, le Mica, un substrat lisse et transparent, a été utilisé comme substrat pour le graphène. Le dopage induit par le mica a été étudié ainsi que son impact sur la sensibilité du graphène au gaz d’ammoniac. Ceci a permis de mettre en évidence le fait que le substrat joue un rôle important pour la détection de l’ammoniac. De plus, ces capteurs fabriques sur mica et SiO2 ont été testés sous différentes conditions de températures et d’oxygène. Dans une autre approche, un polymère a été utilisé pour doper le graphène. Une étude détaillée a été menée pour analyser le comportement de ce graphène fonctionnalisé par rapport aux molécules d’eau. Ces nouveaux résultats expérimentaux obtenus pendant cette thèse constituent un bon support à plusieurs résultats théoriques établis et permettent d’optimiser la conception des capteurs de gaz à base de graphène pour des meilleures performances. / In this research, we report on a study of graphene based gas and humidity sensors. This study could be useful not only to improve the performance of graphene based sensors but also to better understand the interaction between graphene and gas molecules. This seems necessary to promote the applications of graphene as a promising material for gas sensing. Significant advances have been made to design and fabricate these sensors: the different electrical characterizations as well as other techniques used to analyze the mechanism controlling the detection of gas/vapor molecules. These tools have been set up to design and manufacture various sensor structures using different underlying substrates for graphene on one hand and chemical modification of graphene properties on the other hand. The characterization of these sensors under different environments was used to compare the different responses of the sensors and draw several conclusions about gas sensing mechanism. Indeed, Mica, a smooth and transparent substrate, was used as a supporting substrate for graphene. Doping induced to graphene by mica and its impact on graphene sensitivity to ammonia gas were studied. This has made it possible to highlight the fact that the substrate plays an important role for the detection of ammonia. In addition, these sensors made on mica and SiO2 were tested under a variety of temperatures and oxygen. In another approach, a polymer was used to dope graphene. A detailed study was realized about the behavior of water molecules on functionalized graphene. The obtained experimental results, reported for the first time, represent a good support for several theoretical studies already made and could be used to optimize the design of graphene based gas sensors.