Aluminum alloys are widely used materials in the aircraft industry due to their high specific strength and durability. The natural corrosion resistance of aluminum can be improved through an electrochemical anodizing process. Due to recent restrictions in the use of chromic acid with toxic hexavalent chromium as electrolyte, the industry has shifted towards the use of the functional comparable tartaric sulfuric acid (TSA). TSA anodizing provides a porous alumina layer with good corrosion resistance, yet there is a desire to tune the process to fit other purposes. For instance, ice accretion to aircraft surfaces implies a safety risk and reduced energy efficiency. Due to insufficient active anti-icing systems, aircraft manufacturers are in the search for passive anti-acing materials. The ice adhesion properties of a material are thought to be affected by wettability. In turn, the wettability is affected by the morphology of the alumina influenced by the anodizing conditions. Herein, the effects of the anodizing voltage, electrolyte temperature and anodizing time on the morphology and wettability of TSA-anodized aluminum alloy 2024-T3 were studied by scanning electron microscopy (SEM) and contact angle (CA) measurements. The morphology in relation to wettability and ice adhesion strength as well as the use of posttreatments such as hydrothermal sealing and silanization was investigated. SEM images show a clear influence by the anodizing conditions on the porosity, interpore distance and pore diameter of the porous alumina. The morphology has influence on the wettability although the relationship needs further investigation. A superhydrophobic surface obtained by silanization of a surface anodized at high voltage characterized by a rod-like morphology has potential as a passive anti-icing surface. Future work may include additional polishing pretreatments, testing of additional parameters, investigating the CA hysteresis and roll-off angle as well as measuring the adhesion strength of high-impact ice. By tuning the morphology of sustainable anodic coatings, the research area is one step closer to implementing passive anti-icing materials in aircrafts.

O objetivo deste estudo foi analisar a influência da irradiação com lasers de alta intensidade antes da obturação de canais radiculares com cimentos endodônticos resinosos no selamento lateral. Dentes permanentes humanos (n=36) foram endodonticamente tratados e, então, divididos aleatoriamente em nove grupos experimentais (n=4), de acordo com o tratamento dentinário subsequente. Os grupos foram: G1(N-Rickert/sem laser) ; G2(Epiphany SE®/sem laser); G3(EndoREZ®/sem laser); G4(N-Rickert/laser Nd:YAG); G5(Epiphany SE®/laser Nd:YAG); G6 (EndoREZ®/ laser Nd:YAG); G7(N-Rickert/laser Er:YAG); G8(Epiphany SE®/laser Er:YAG)e G9 (EndoREZ®/ laser Er:YAG).Os parâmetros utilizados para o lasers foram: laser de Nd:YAG (1,5 W, 100 mJ, 15 Hz) e laser de Er:YAG (1 W, 100 mJ, 10 Hz). Todos os dentes foram obturados pelo mesmo operador, utilizando a técnica do cone único para os elementos obturados com os cimentos resinosos e cones múltiplos quando utilizado o cimento de N-Richert. Os cimentos estudados foram preparados conforme as instruções dos fabricantes. Após decorrido o tempo de espera de pressa total de todos os cimentos obturadores os espécimes tiveram sua superfície radicular impermeabilizada com Araldite, em toda a sua extensão. Tubos de microcentrífuga de 1,5 mililitros foram cortados em uma das extremidades e o dente foi inserido até que o ápice ficasse localizado externamente. O espaço existente entre a superfície radicular e o tubo de microcentrífuga foi selado com Araldite, esse selamento proporcionou o vedamento da porção inferior do tubo. Após isto os conjuntos foram submetidos processo de esterilização por óxido de etileno a uma temperatura de 56ºC por quatro horas. Os tubos foram imersos em vidros tipo penicilina que continham 5ml de BHI previamente estéreis. Colônias de Enterococcus faecalis foram semeadas dentro dos tubos, para observar ou não a percolação marginal dos cimentos estudados através da turvação do meio de cultura, por um período de 45 dias. Observou que os dentes dos G1, G3 e G8 0% de contaminação, G4, G5 e G6 50% de espécimes contaminadas, G2 e G9 75% de elementos contaminados e G7 100% dos espécimes contaminados após o período de avaliação. / The aim of this in vitro study was to analyze two high power lasers irradiation effects before the root canal filling procedure with resin endodontic cements on the lateral sealing. Thirty-six permanent human molars were endodontically treated and randomly assigned in nine experimental groups (n=4) according with the subsequent dentin treatment. The groups were as follows: G1 (N-Rickert); G2 (Epiphany SE®); G3 (Endo REZ®); G4 (N-Rickert / Nd:YAG laser irradiation); G5 (Epiphany SE® / Nd:YAG laser irradiation); G6 (EndoREZ® / Nd:YAG laser irradiation); G7 (N-Rickert / Er:YAG laser irradiation); G8 (Epiphany SE® / Er:YAG laser irradiation) and G9 (EndoREZ® / Er:YAG laser irradiation). The laser parameters used were: Nd:YAG laser (1064 nm) at 1.5W, 100 mJ, 15 Hz; and Er:YAG laser (2940 nm) at 1.0 W, 100 mJ, 10Hz. All the teeth were filled by the same operator using the single cone technique for the elements filled with resin cements and multiple cones when the NRickert cement was used. The analyzed cements were prepared following the manufacturers recommendations. After the waiting and total setting time of all the root canal filling materials all the samples were coated along their root surfaces with Araldite®. Micro centrifuge tubes of 1.5 ml were cut in one of the edges and the samples were introduced until their apexes were externally located. The space between the root surface and the micro centrifuge tubes was sealed with Araldite® in order to seal the inferior tube portion. Following this, all samples were sterilized by ethylene oxide at a temperature of 56oC for four hours. The tubes were immersed in penicillin glasses with 5 ml of BHI previously sterilized. Enterococcus faecalis colonies were sought inside the tubes in order to observe a possible marginal percolation of the studied cements through a culture media turbidity process for a period of 45 days. It was possible to observe after the evaluation period an absence of contamination (0%) on samples from G1, G3 and G8; 50% of contamination on samples from G5 and G6; 75% of contamination on samples from G2 and G9 and 100% of contamination on samples from G7.

O objetivo deste estudo foi avaliar, in vitro, a capacidade seladora de três materiais obturadores endodônticos, com a proposição de uma nova forma de quantificação da infiltração e um novo agente traçador, utilizando um sistema semelhante ao do modelo experimental da glicose. Trinta e seis dentes unirradiculares extraídos tiveram as coroas removidas, permanecendo 12 mm das raízes. Os canais radiculares foram instrumentados e obturados com o sistema Epiphany (GE) ou com a condensação lateral da guta-percha e cimentos AH Plus (GA) ou Sealapex (GS). Com o auxílio de um calcador aquecido removeu-se 7 mm de material obturador. Seis espécimes com os canais completamente obturados tiveram as raízes totalmente impermeabilizadas com duas camadas de esmalte de unhas, constituindo o grupo controle negativo. Os espécimes foram separados em dois grupos para a realização de dois experimentos que diferiram quanto ao modo de adaptação do espécime no sistema (cianoacrilato ou resina epóxi). Uma solução de cafeína (pH 6.0) foi forçada no sentido coronário com uma pressão hidrostática de 2.55 kPa em direção apical. A infiltração foi medida em ng/mL, pela concentração de cafeína na solução receptora do reservatório, em intervalos de 10, 30 e 60 dias. Para a quantificação foi utilizada a cromatografia líquida de alta eficiência acoplada à espectrometria de massas (CLAE-EM/EM). Esta técnica apresentou alta sensibilidade e especificidade na quantificação do agente traçador. Em função da limitação dos agentes de vedação (cianoacrilato e resina epóxi) empregados no modelo experimental, não foi emitida conclusões a respeito da capacidade seladora dos materiais obturadores testados. / The objective of this study was to propose a new way to measure infiltration with a new tracing agent by using a system similar to that of the glucose penetration model. Thirty-six single-root extracted teeth had their root canals filled using the Epiphany system or with a lateral condensation of gutta-percha and AH Plus or Sealapex cement. Two experiments were carried out that used a different mode of adapting the specimen within the system (cyanoacrylate or epoxy resin). A caffeine solution (pH 6.0) was forced in a coronary direction with a hydrostatic pressure of 2.55 kPa towards the tooth apex. The infiltration was measured in ng/mL, by the concentration of caffeine in the receptor solution of the apical reserve at intervals of 10, 30, and 60 days. To quantify the measurements, a high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) was used. This technique showed a high sensitivity and specificity for quantifying the tracing agent. Due to the limitations of the sealing agents (cyanoacrylate and epoxy resin) used in our experimental model, analysis of the sealing ability of the filling materials tested was not performed. It is necessary to carefully validate the principal variables of the systems that assess infiltration in order to standardize studies and give greater credibility to their results.

Foram realizados dois experimentos visando avaliar diferentes estratégias de vedação para silos do tipo trincheira. No experimento I, objetivou-se avaliar as características fermentativas, composição química e perdas de matéria seca e de matéria orgânica em silagens de milho vedadas com diferentes tipos de filmes plásticos e com ou sem a adição de camada de bagaço de cana. Os tratamentos utilizados foram: ETNC: filme dupla face de polietileno com 200 ?m de espessura; ETC: filme dupla face de polietileno com 200 ?m de espessura recoberto com camada de 10 cm de bagaço de cana e ET+ADNC: filme co-extrusado dupla face de poliamida e polietileno, com 120 ?m de espessura. O delineamento experimental foi de blocos casualizados. Os dados foram submetidos à análise de variância e suas médias foram comparadas pelo teste Tukey, a 5% de signigicância. A quantidade de silagem deteriorada foi menor para o tratamento ETC, enquanto que os demais tratamentos foram semelhantes entre si. Não foi observada diferença significativa entre os tratamentos para a composição bromatológica, entretanto, observou-se diferença para entre os diferentes pontos amostrados (TL: topo lateral, TC: topo central e C: centro) para as variáveis MS, FDA, amido, hemicelulose e DVIVMO, sendo que os piores resultados foram encontrados nas regiões periféricas (TL e TC) dos silo. Os tratamentos não influenciaram na contagem de microrganismo (BAL: bactérias ácido láticas, FF: fungos filamentosos e LEV: leveduras), porém, com relação ao local de coleta houve diferença para BAL e FF. Como esperado, a população de FF foi maior na periferia dos silos, enquanto que a de BAL foi maior no centro. A contagem de leveduras não sofreu influência do tratamento e local de amostragem. No experimento II, objetivou-se avaliar o desempenho animal em função da estratégia de vedação de silagens de milho. Foram utilizadas 15 vacas distribuídas aleatoriamente em cinco quadrados latinos 3x3, com períodos de 21 dias. Os animais foram mantidos em sistema de confinamento Tie-Stall com baias individuais e alimentadas duas vezes ao dia. Os tratamentos foram definidos de acordo com o método de vedação: ETNC, ETC e ET+ADNC. As dietas foram formuladas para serem isoproteicas, com 53% de silagem de milho (% MS). As porções deterioradas das silagens foram descartadas diariamente, as rações foram preparadas utilizando apenas silagem não deteriorada. O consumo de matéria seca, a produção e composição do leite foram determinados entre os dias 15 e 21 de cada período experimental. Os dados foram analisados utilizando o Proc Mixed, do software estatístico SAS. Os tratamentos ET+ADNC e ETC apresentaram maior eficiência energética enquanto que os tratamentos ET+ADNC e ETNC tiveram tendência de maior produção de leite corrigido para 3,5% de gordura e excreção de energia no leite; da mesma forma, a excreção de proteína no leite também foi aumentada. O tratamento ETC não promoveu melhoras no valor nutritivo das silagens, enquanto que os tratamentos ET+ADNC e ETNC apresentaram tendência em maximizar o desempenho das vacas. / Two experiments were conducted to evaluate different strategies to cover silos. The experiment I evaluate the chemical fermentation profile, chemical composition and losses of dry matter and organic matter in corn silage covered with different types of plastic film and with or without the added layer of sugarcane bagasse. The treatments were: ETNC: 200?m black-on-white polyethylene film; ETC: black-on-white polyethylene film plus sugarcane bagasse over the film and ET+ADNC: 125?m polyamide/polyethylene coextruded film. The experimental design was randomized blocks. The data were subjected to analysis of variance and their means were compared by Tukey test at 5% significance. The amount of spoiled silage was lower for treatment ETC, while the other treatments were similar. There was no significant difference between treatments for the chemical composition, although differences were observed between different sampling sites (TL: side wall, TC: top center and C: bottom) for the variables DM, ADF, starch, hemicellulose and IVOMD, while the worst results were found in the peripheral regions (TL and TC) of the silo. Treatments did not affect the count of microorganisms (BAL: lactic acid bacteria, FF: filamentous fungi: LEV: yeasts), however the FF acount was greater in the TL and TC, while BAL was higher in the C. The yeast count was not influenced by treatment or sampling site. In the experiment II was evaluated performance of dairy cows fed corn silage covered with different sealing strategies. Fifteen lactating cows were randomly assigned to 5 replicated 3×3 Latin square design with 21-d periods. Animals were housed in sand-bedded tie-stall barn and individually fed ad libitum to achieve approximately 10% refusals twice daily. Treatments were defined according to the method of sealing: ETNC, ETC and ET+ADNC. Diets were formulated to be isonitrogenous with 53% corn silage (DM%) to meet the nutrient requirements of a dairy cow producing 35 kg×d-1 of milk. The deteriorated inedible silage was discarded every day and only edible silage was used to prepare the total mixed rations. Dry matter intake (DMI) and milk yield were recorded from d-15 to d-21 in each period, as well milk composition. Data were analyzed using the Mixed procedure of SAS. Treatments ET+ADNC and ETC showed higher energy efficiency while treatments ET+ADNC and ETNC tended to higher milk yield and energy excretion in milk, as well the excretion of protein in the milk was also increased. Contrary to expected, the ETC treatment did not improve the nutritive value of silages. In conclusion, treatments ET+ADNC and ETNC tended to maximize the performance of dairy cows.

Les séismes le long de grandes failles crustales représentent un danger énorme pour de nombreuses populations. Le mécanique de ces failles est influencé par des zones endommagées qui entourent le coeur de faille. La fracturation dans ces zones contrôle chaque étape du cycle sismique. En effet, cette zone contrôle la mécanique de la rupture sismique, elle est un conduit pour les fluides, réagit chimiquement sous l'effet de fluides réactifs, et facilite la déformation pendant les périodes post- et inter-sismiques. Dans cette thèse de doctorat, des expériences de laboratoire ont été réalisées pour mieux comprendre 1) la façon dont l'endommagement est généré pendant le chargement transitoire co-sismique, 2) comment l'endommagement permet de mieux contraindre le chargement co-sismique le long de grandes failles, et iii) comment les fractures peuvent se cicatriser au fil du temps et contrôler l'évolution de la perméabilité et de la résistance mécanique de la faille.L'introduction de la thèse propose une revue critique de la littérature sur la génération de dommages co-sismiques et en particulier sur la formation des roches pulvérisées. Le potentiel de ces roches comme marqueur des déformations co-sismiques est discuté. Bien que ces roches pulvérisées soient prometteuses pour ces aspects, plusieurs questions restent ouvertes.L'une de ces questions concerne les conditions de chargement transitoire nécessaires pour atteindre la pulvérisation. Le seuil de taux de deformation pour atteindre la pulvérisation peut être réduit par des endommagemments progressifs, au cours de ruptures sismiques successives. Des barres de Hopkinson ont été utilisées pour effectuer des chargements dynamique successifs d'une roche cristalline (monzonite). Les résultats montrent que le seuil pour atteindre la pulvérisation est réduit d'au moins 50% lorsque des chargements successives sont imposés. Cette thèse discute aussi pourquoi les roches pulvérisées sont presque toujours observées dans des roches cristallines et peu dans des roches sédimentaires poreuses. Pour comprendre cette observation, des expériences à haute vitesse de déformation ont été effectuées sur des grès de Rothbach. Les résultats montrent que la pulvérisation des grains eux mêmes ne se produit pas dans les grès. L'endommagement reste se produit principalement à une échelle supérieure à celle grains, et des bandes de compaction sont observées. La compétition entre l'endommagement inter- et intra-granulaire est expliquée par les paramètres microstructuraux en combinant deux modèles micromécaniques classiques. Les microstructures observées dans les grès peuvent se former dans le régime quasi-statiques et aussi dans le régime dynamique. Par conséquent, il est recommandée d'être prudent lors de l'interprétation du mécanisme de deformation dans les roches sédimentaires proches de la surface. La dernière question abordée durant la thèse est la cicatrisation post-sismique de fractures co-sismiques. Des expériences ont été réalisées pour cicatriser des fissures par précipitation de calcite. Le but est l'étude du couplage entre l'augmentation de résistance mécanique de la roche fissurée et l'évolution de la perméabilité. Les échantillons fracturées ont été soumis à des conditions de pression et températures similaires de la croûte supérieure et à une percolation d'un fluide sursaturé en calcite pendant plusieurs mois. Ce couplage non-existe dans les premières étapes de la cicatrisation. Il est révélé par l'imagerie par tomographie aux rayons X que le scellement naissant des fractures se produit dans les porosités situées en aval de barrières d'écoulement, et donc dans des régions qui ne touchent pas les principales voies d'écoulement du fluide. Le découplage entre l'augmentation de résistance de la roche et la perméabilité suggère que les zones d'endommagement peu profondes dans les failles actives peuvent rester des conduits actifs pour les fluides plusieurs années après un séisme. / Earthquakes along large crustal scale faults are a huge hazard threatening large populations. The behavior of such faults is influenced by the fault damage zone that surrounds the fault core. Fracture damage in such fault damage zones influences each stage of the seismic cycle. The damage zone influences rupture mechanics, behaves as a fluid conduit to release pressurized fluids at depth or to give access to reactive fluids to alter the fault core, and facilitates strain during post- and interseismic periods. Also, it acts as an energy sink for earthquake energy. Here, laboratory experiments were performed to come to a better understanding of how this fracture damage is formed during coseismic transient loading, what this fracture damage can tell us about the earthquake rupture conditions along large faults, and how fracture damage is annihilated over time.First, coseismic damage generation, and specifically the formation of pulverized fault damage zone rock, is reviewed. The potential of these pulverized rocks as a coseismic marker for rupture mechanisms is discussed. Although these rocks are promising in that aspect, several open questions remain.One of these open questions is if the transient loading conditions needed for pulverization can be reduced by progressively damaging during many seismic events. The successive high strain rate loadings performed on quartz monzonites using a split Hopkinson pressure bar reveal that indeed the pulverization strain rate threshold is reduced by at least 50%.Another open question is why pulverized rocks are almost always observed in crystalline lithologies and not in more porous rock, even when crystalline and porous rocks are juxtaposed by a fault. To study this observation, high strain rate experiments were performed on porous Rothbach sandstone. The results show that pervasive pulverization below the grain scale, such as observed in crystalline rock, does not occur in the sandstone samples for the explored strain rate range (60-150 s-1). Damage is mainly occurs at a scale superior to that of the scale of the grains, with intragranular deformation occurring only in weaker regions where compaction bands are formed. The competition between inter- and intragranular damage during dynamic loading is explained with the geometric parameters of the rock in combination with two classic micromechanical models: the Hertzian contact model and the pore-emanated crack model. In conclusion, the observed microstructures can form in both quasi-static and dynamic loading regimes. Therefore caution is advised when interpreting the mechanism responsible for near-fault damage in sedimentary rock near the surface. Moreover, the results suggest that different responses of different lithologies to transient loading are responsible for sub-surface damage zone asymmetry.Finally, post-seismic annihilation of coseismic damage by calcite assisted fracture sealing has been studied in experiments, so that the coupling between strengthening and permeability of the fracture network could be studied. A sample-scale fracture network was introduced in quartz monzonite samples, followed exposure to upper crustal conditions and percolation of a fluid saturated with calcite for several months. A large recovery of up to 50% of the initial P-wave velocity drop has been observed after the sealing experiment. In contrast, the permeability remained more or less constant for the duration of the experiment. This lack of coupling between strengthening and permeability in the first stages of sealing is explained by X-ray computed micro tomography. Incipient sealing in the fracture spaces occurs downstream of flow barriers, thus in regions that do not affect the main fluid flow pathways. The decoupling of strength recovery and permeability suggests that shallow fault damage zones can remain fluid conduits for years after a seismic event, leading to significant transformations of the core and the damage zone of faults with time.

L’augmentation des températures et des pressions de travail des centrales de production d’énergie représente un enjeu considérable en termes de réduction d’émission de polluants et d’augmentation d’efficacité énergétique. Pour cela, des matériaux plus performants par rapport à ceux employés actuellement doivent être utilisés afin de résister aux environnements sévères (hautes températures, 100% vapeur d’eau, pression…). Malgré les bonnes propriétés mécaniques de bon nombre d’aciers, l’application d’un revêtement protecteur capable de former une couche d’oxyde dense, protectrice et stable à haute température, est essentielle. Ainsi, dans le cadre du projet Européen FP-7 « POEMA », nous nous sommes intéressés aux mécanismes de formation de revêtements de diffusion d’aluminium sur des aciers ferrito-martensitiques et austénitiques fréquemment employés dans ce type de centrales. Des études sur la colmatation des fissures éventuellement parues durant l’aluminisation des aciers ont été également réalisées. Les mécanismes de dégradation des revêtements B2-(Fe (Ni))Al ont ensuite été étudiés sous 100% vapeur d’eau et sous air à 650 et 700°C jusqu’à 10000 heures et sous différentes pressions (1 et 300 bar). Nous avons démontré que la pré-oxydation induite lors de l’élaboration du revêtement permet de faire croître une fine couche protectrice de α-Al2O3 qui se développe au cours de l’oxydation. Cependant, les longues expositions sous fortes pressions de vapeur promeuvent la diffusion cationique de Fe, ceci donnant lieu à des petits nodules surfaciques d’oxyde. Enfin, les mécanismes de dissolution des revêtements avec un acide dilué ont été étudiés afin de montrer la possibilité de décaper puis de réaluminiser les matériaux initialement revêtus. / Higher energy efficiencies can be achieved by the increase of temperatures and pressures in power plant, thus allowing the reduction of the polluting emissions. Therefore, more efficient materials, compared to those currently employed, have to be used in order to resist to harsh environmental conditions (high temperatures, steam, pressure…). Despite of the good mechanical properties of many steels, the elaboration of a protective coating able to form a dense, protective and stable oxide layer at high temperature, is necessary. Thus, in the framework of the “POEMA” European project, the mechanisms of the formation of aluminium diffusion coatings were studied on ferritic-martensitic and austenitic stainless steels that are currently employed in power plants. The sealing of cracks eventually created during the aluminisation of steels was also studied. The degradation mechanisms of the B2-(Fe (Ni))Al coatings were then studied in steam and in air at 650 and 700°C up to 10000 hours and under different pressures (1 and 300 bar). We have demonstrated that the pre-oxidation induced during the elaboration of coatings grew a thin protective oxide scale composed of α-Al2O3 which developed further upon oxidation. Nevertheless, the long exposures under high steam pressures promoted the cationic diffusion of Fe, thus allowing the formation of small surface oxide nodules. Finally, the dissolution mechanisms of coatings with a diluted acid have been studied in order to demonstrate the possibility of strip and realuminise the materials initially coated.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 164-176).

No description available.

Fuel cells represent a promising energy alternative to the traditional combustion of fossil fuels. In particular, solid oxide fuel cells (SOFCs) have been of interest due to their high energy densities and potential for stationary power applications. One of the key obstacles precluding the maturation and commercialization of planar SOFCs has been the absence of a robust sealant. A leakage computational model has been developed and refined in conjunction with leakage experiments and material characterization tests at Oak Ridge National Laboratory to predict leakage in a single interface metal-metal compressive seal assembly as well as multi-interface mica compressive seal assemblies. The composite model is applied as a predictive tool for assessing how certain parameters (i.e., temperature, applied compressive stress, surface finish, and elastic thermo physical properties) affect seal leakage rates.

This thesis devotes to develop a wafer-level packaging technique of the planar AgCl-based micro reference electrode and to investigate its various electrochemical characteristics (including the potential stability and offset voltage, AC impedance, cyclic-voltammetry analysis, electrochemical noise and reproducibility). The miniaturized all-solid-state reference electrode can integrated with many biomedical or biochemical sensors for substantially reduce the dimension of the whole sensing system and improve the commercial capability of portable detecting products. This study reports firstly a smallest module of the micro reference electrode with dimension only about 9 mm (L) ¡Ñ 6 mm (W) ¡Ñ 1 mm (H) in the worldwide using the silicon bulk-micromachining technology, thin film deposition and chloridation techniques. The packaged reference electrode module is constructed by two bonded wafers with different functions. One wafer of this module is defined as ¡§electrode chip¡¨ and it has a Ti/Pd/Ag/AgCl planar quasi-reference electrode deposited on its surface. Another wafer is called as ¡§packaging chip¡¨ and it has two bulk-micromachined silicon cavities for the filling/sealing of 1.33 ~ 6.40 £gL KCl-gel (as the salt-bridge of electrode) and electrical connection. Many electrochemical characteristics of the encapsulated solid-state micro reference electrode are tested and improved for the commercial applications. Including a very stable cell potential (<4 mV in 30000 sec.), an approximately zero offset-voltage, a low AC impedance (1~20 K£[), and high reproducibility (drift less than 3~8 mV in 30000 sec. and the range of offset voltage is -6 ~ 3 mV) of the packaged micro reference electrode are demonstrated. Furthermore, stable CV curve of the packaged Ti/Pd/Ag/AgCl/KCl-gel reference electrode were proved by cyclic-voltammetry analysis and its low electrochemical noise spectrum was investigated and discussed in this work. Compared with the commercial reference electrode, the planar miniaturized AgCl reference electrode module developed in this thesis has displayed its many excellent characteristics and with a dimension only 250 times smaller than the conventional reference electrode.