Fuelcells are perspective alternative source of power. Currently used polymer electrolyte membrane. They have good qualities, but they are expensive. This is the reason, why we looking for alternative.This work deal with research qualities polymer electrolyte membrane based on Polyvinylalcohol. This polymer elecrolyte membrane asassembly to MEA structure and research qualities. This qualities based on electrical and non electrical value.

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Yes / Poly(vinyl alcohol) (PVA)/graphene oxide (GO) nanocomposite hydrogel as artificial cartilage replacement was prepared via freezing/thawing method by introducing polyethylene glycol (PEG). Efficient grafting of PVA molecules onto GO surface was realized by formation of hydrogen bonding, resulting in exfoliation and uniform distribution of GO in PVA matrix. By introduction of appropriate content of GO, the increased crystalline regions of PVA and the formation of GO centered second network structure led to the increase of the storage modulus and effective cross-linking density. And therefore the mechanical strength and toughness of the composite hydrogel were improved simultaneously: the tensile strength, elongation at break, and compressive modulus showed approximately 200%, 40%, and 100% increase of the neat PVA hydrogel. Besides, for the sample with 1.5 wt % GO content, the maximum force retention and dynamic stiffness were improved remarkably in the process of sinusoidal cyclic compression, and the compressive relaxation stress also increased significantly, indicating the enhancement of the compressive recoverable and antifatigue ability, and resistance to compressive relaxation by formation of high load-bearing, dense, and reinforcing double network structure. Moreover, more than 50% decrease in coefficient of friction was obtained for the composite hydrogel, and the worn surface presented relative smooth and flat features with sharp decreasing furrow depth, confirming the lubrication effect of GO-PEG. This study shows promising potentials in developing new materials for cartilage replacement with simultaneous combination of high mechanical property and excellent lubrication.

"The effects of molecular weight (Mw) and concentration (c) on the structure of electrospun PVA have been studied. Experiments have been conducted for Mw values ranging from 9000 g/mol to 124,000 g/mol. The concentration was varied from 5 to 35 wt %. Data were acquired for several solvents including water, Dimethyl Sulfoxide, Ethylene Glycol and N-Methyl Pyrrolidone. The transient phenomena occurring during jet breakdown were examined by high speed digital photography. The structure in the electrospun polymer was analyzed by scanning electron microscopy. The fiber diameter distribution for various conditions was characterized by optical image analysis. The effects of additives such as NaCl and Poly Ethylene Glycol on the structure have been studied. The results indicate that a minimum Mw and c corresponding to [h]c ~ 5 or Capillary number, Ca ~ 0.5 is necessary for forming a fibrous structure. As Mw or c increase, the fiber diameter becomes larger and a broader distribution of fibers may be obtained. The average diameter of the fiber, D, follows a Power law relationship: D (nm) = 18.6([h]c)1.11. Round fibers may be obtained at low Mw and c, while flat fibers are observed at high Mw and c. The transition from round to flat fibers appears to begin at [h]c ~ 12. At any [h]c, there is a minimum Capillary and Ohnesorge numbers at which fibers are stabilized and a maximum at which viscous effects become dominant. The addition of NaCl lowers the average fiber diameter in PVA samples with a high molecular weight. Electrospinning can be used to produce nanofibers of PVA with various architectures. "

PVA hydrogels are potential biomaterials for various tissue-engineering applications. PVA hydrogels are relevant to vascular graft development due to their excellent biocompatibility and the capability to possess a wide range of mechanical properties based on compositional and processing parameters. This thesis aims to characterize some PVA hydrogels mechanically, biologically, and physically. A constitutive formulation is used for mechanical characterization, which allows for analysis of any possible stress-strain configuration applied to the material. A bovine aortic endothelial cell adhesion study under physiologic blood flow conditions comprises the biologic characterization, which gives insight into how human endothelial cells might interact with PVA hydrogels in a vascular graft application. A high-resolution SEM study is used to physically characterize the material, which furthers the understanding of the reactions of this material in vivo. These characterizations of PVA hydrogels will aid in the development of tissue-engineered products, in particular, the potential use as a vascular grafting biomaterial.

Data is all around us, everywhere we go and in every activity we do. It exists in all aspects of our everyday personal life. Making sense of these personal daily data, which leads to more self-awareness is becoming remarkably important as we can learn more about our habits and behavior and therefore we can reflect upon this extended self-knowledge. Particularly, these data can assist people to learn more about themselves, uncover existing patterns in their behaviors or habits and help them to take action towards newly developed goals. Accordingly, they can either try to improve their behaviors to gain better results and trends or to maintain existing ones. Through the interviews that I conducted, I learned that “Productivity” is one of the most important personal attributes that people are very interested to monitor, track and improve in their daily lives. People are interested to learn more about the supportive or preventive causes that effect their daily productivity, which eventually can help them to improve their time-management and self-management. In this thesis, I focus on two research questions: (1) How can we design a visualization tool to help people be more engaged in understanding their daily productivity? In order for people to learn more about themselves, they need context about their living habits and activities. So I chose digital calendars as a platform to integrate productivity related information as they provide beneficial contextual information, supporting many of the questions that people ask themselves about their personal data. As the next step, I had to find an effective way of representing influential factors on productivity on the calendar. This led to define my second research question: (2) What combination of visual encodings will enable people to most easily identify a relationship between two different pieces of daily information rendered on a calendar? For finding the best visual encoding, I considered encoding Numeric data using Saturation and Length encodings, and Nominal data using Shape encoding. I designed two types of questions: Calendar related questions, to investigate the interference level of visualizations in calendar related tasks, and Visualization related questions to identify which visualization is faster and leads to more accurate results and better user ratings. I compared the combination of Numeric x Numeric (Saturation x Saturation, Saturation x Length, Length x Length) and Numeric x Nominal (Shape x Length, Shape x Saturation) data encodings. My results demonstrated the following: for Calendar Task questions and in Numeric x Numeric category, Length x Length had the overall best results. For the same task set and in Numeric x Nominal category, Shape x Length was rated the best. For Visualization Task questions and in Numeric x Numeric category, Saturation x Saturation had the better performance overall in most of the cases and for same task set and in Numeric x Nominal category, Shape x Saturation was the fastest while Shape x Length was the most accurate. These findings along with interviews provided me with useful information for refining the visualization designs to more accurate, more user-friendly and faster visualizations which assist people in monitoring goals, trends, status, contexts, influencing factors and differences in their productivity related personal daily data and brings them more insight awareness and possibly self-reflection. / Graduate / 0984 / tavakkol@uvic.ca

Data is all around us, everywhere we go and in every activity we do. It exists in all aspects of our everyday personal life. Making sense of these personal daily data, which leads to more self-awareness is becoming remarkably important as we can learn more about our habits and behavior and therefore we can reflect upon this extended self-knowledge. Particularly, these data can assist people to learn more about themselves, uncover existing patterns in their behaviors or habits and help them to take action towards newly developed goals. Accordingly, they can either try to improve their behaviors to gain better results and trends or to maintain existing ones. Through the interviews that I conducted, I learned that “Productivity” is one of the most important personal attributes that people are very interested to monitor, track and improve in their daily lives. People are interested to learn more about the supportive or preventive causes that effect their daily productivity, which eventually can help them to improve their time-management and self-management. In this thesis, I focus on two research questions: (1) How can we design a visualization tool to help people be more engaged in understanding their daily productivity? In order for people to learn more about themselves, they need context about their living habits and activities. So I chose digital calendars as a platform to integrate productivity related information as they provide beneficial contextual information, supporting many of the questions that people ask themselves about their personal data. As the next step, I had to find an effective way of representing influential factors on productivity on the calendar. This led to define my second research question: (2) What combination of visual encodings will enable people to most easily identify a relationship between two different pieces of daily information rendered on a calendar? For finding the best visual encoding, I considered encoding Numeric data using Saturation and Length encodings, and Nominal data using Shape encoding. I designed two types of questions: Calendar related questions, to investigate the interference level of visualizations in calendar related tasks, and Visualization related questions to identify which visualization is faster and leads to more accurate results and better user ratings. I compared the combination of Numeric x Numeric (Saturation x Saturation, Saturation x Length, Length x Length) and Numeric x Nominal (Shape x Length, Shape x Saturation) data encodings. My results demonstrated the following: for Calendar Task questions and in Numeric x Numeric category, Length x Length had the overall best results. For the same task set and in Numeric x Nominal category, Shape x Length was rated the best. For Visualization Task questions and in Numeric x Numeric category, Saturation x Saturation had the better performance overall in most of the cases and for same task set and in Numeric x Nominal category, Shape x Saturation was the fastest while Shape x Length was the most accurate. These findings along with interviews provided me with useful information for refining the visualization designs to more accurate, more user-friendly and faster visualizations which assist people in monitoring goals, trends, status, contexts, influencing factors and differences in their productivity related personal daily data and brings them more insight awareness and possibly self-reflection. / Graduate / 0984 / tavakkol@uvic.ca

Electrospinning has provided the opportunity to create extracellular matrix (ECM) mimicking scaffolds for the development of tissue-engineered constructs. Within Professor Kristen Cardinal’s Blood Vessel Mimic (BVM) Lab, at Cal Poly, there exists a constant demand for innovation and the expansion of polymer types and electrospinning capabilities for its BVM model. Along these lines, the BVM Lab has recently acquired two new electrospinning systems: the Spinbox, a commercially graded electrospinning system, and the Learn-By-Doing system, which was part of a recently completed thesis conducted by Jason Provol. Additionally, recently published literature has demonstrated polyvinyl alcohol (PVA) as a viable option for creating electrospun scaffolds in the nanometer range. These findings prompt interest in investigating this polymer type due to its potential for producing extremely thin fiber diameters. Therefore, the overall objective of this thesis was to enhance the electrospinning capabilities of the BVM Lab through the utilization of the water-soluble polymer, PVA and to comprehensively compare the three available electrospinning systems within the BVM Lab, for novel tissue engineering or classroom applications. The work performed in this thesis was structured around three main Aims. The first Aim of this thesis was to demonstrate the feasibility of using PVA to create flatsheet scaffolds using the Spinbox system. To achieve this, different PVA types with varying degrees of hydrolysis (DH) and molecular weight (MW) were spun to determine the most suitable PVA formulation. These experiments revealed that PVA with low DH and ultra-high MW was the most suitable for electrospinning. Subsequently, a formal Design of Experiments (DOE) was conducted to determine an effective parameter combination for Spinbox flatsheets. The DOE yielded a parameter combination with a voltage of 27 kV, a flow rate of 0.50 ml/hr, a gap distance of 17 cm, and a weight percentage of 10%. The selection of a PVA formulation with appropriate parameters in Aim 1 established the groundwork for accomplishing the objectives of Aim 2. Aim 2 sought to extend PVA’s electrospinning utility to other collector geometries across all three of the BVM lab’s electrospinning systems, while also comparing the usability, safety, and adjustability of each system relative to one another. This was the first time all 3 systems were directly compared. The results from Aim 2 demonstrated the reproducibility of tubular scaffolds on both the Custom and Spinbox systems, featuring nanoscale fibrous scaffolds, as well as on the LBD system with flatsheets. Furthermore, a qualitative comparison of the systems indicated that the Spinbox exhibited the highest degree of adjustability and safety among the electrospinners, albeit with the lowest relative degree of usability. Conversely, the LBD system demonstrated the highest usability or intuitiveness, while also being the most hazardous and least adjustable of the systems. The Custom system ranked in the middle for all three metrics. Finally, the successful creation of tubular PVA scaffolds led to Aim 3 of this thesis, which focused on evaluating the potential of PVA scaffolds in a bioreactor environment for research applications and devising an accessible classroom PVA protocol for teaching applications. To accomplish this final aim, the scaffolds produced in Aim 2 were characterized and evaluated based on their solubility in cell-media. Additionally, methods for enhancing water-resistance through methanol cross-linking were explored and assessed. The results indicated that cross-linking PVA with methanol could enhance water resistance, but additional treatment would be necessary for PVA to serve as a standalone vascular scaffold in BVMs. However, a PVA Lab protocol was successfully developed to facilitate classroom education, providing a tangible and immediately impactful outcome of this thesis.

Os hidrogéis estão dentre as matrizes poliméricas mais utilizadas em tecnologia farmacêutica em razão de sua vasta aplicação e funcionalidade, especialmente em sistema de liberação de fármacos. Tendo em vista o grande avanço nas inovações dos produtos cosméticos, tanto por meio da introdução de novos princípios ativos quanto pelas matrizes utilizadas para liberação controlada dos mesmos, o objetivo deste trabalho foi incorporar e avaliar a liberação de um princípio ativo natural, o ArctAlg®, em membranas de hidrogel, de modo a obter um dispositivo de liberação para fins cosméticos. O ArctAlg® é um extrato aquoso que possui uma excelente ação anti-oxidante, lipolítica, anti-inflamatória e citoestimulante. Foi realizado o estudo das propriedades mecânicas, físicoquímicas e a biocompatibilidade in vitro das membranas de hidrogéis de poli(vinil- 2- pirrolidona) (PVP) e poli(vinil álcool) (PVA) obtidas pela reticulação por radiação ionizante. A caracterização físico-química das matrizes poliméricas foi obtida pelos ensaios de fração gel e intumescimento e o de biocompatibilidade in vitro pelo ensaio de citotoxicidade pelo método de incorporação do vermelho neutro. No ensaio de fração gel tanto o hidrogel de PVP quanto o de PVA apresentaram um alto grau de reticulação. O hidrogel de PVP apresentou uma maior porcentagem de intumescimento em relação ao de PVA e no ensaio de citotoxicidade os hidrogéis mostraram-se atóxicos. A propriedade citoestimulante do ArctAlg® foi verificada no ensaio de citoestimulação com células fibroblásticas de pele de coelho, em que foi evidenciado um aumento de cerca de 50% das células quando em contato com 0,5% do princípio ativo. As membranas de hidrogel preparadas com 3% de ArctAlg® foram submetidas ao ensaio de liberação em incubadora a 37ºC e as alíquotas coletadas durante o ensaio foram quantificadas por cromatografia líquida de alta eficiência (HPLC). Os resultados obtidos na cinética de liberação mostraram que as membranas de hidrogel de PVP liberaram cerca de 50% do ArctAlg® incorporado e as de PVA em cerca de 30%. No ensaio de citoestimulação do ArctAlg® liberado, o dispositivo de PVP apresentou um aumento em cerca de 80% da população celular em relação ao controle do ensaio, mostrando ser o dispositivo mais indicado para ser utilizado em processos de reparação cutânea. / In pharmaceutical technology hydrogel is the most used among the polymeric matrices due to its wide application and functionality, primarily in drug delivery system. In view of the large advance innovations in cosmetic products, both through the introduction of new active agents as the matrices used for its controlled release, the objective of this study was to evaluate the release and immobilization of a natural active agent, the Arct\'Alg® in hydrogel membranes to obtain a release device for cosmetics. Arct\'Alg® is an aqueous extract which has excellent anti-oxidant, lipolytic, anti-inflammatory and cytostimulant action. Study on mechanical and physical-chemical properties and biocompatibility in vitro of hydrogel membranes of poly(vinyl-2- pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) obtained by ionizing radiation crosslinking have been performed. The physical-chemical characterization of polymeric matrices was carried out by gel fraction and swelling tests and biocompatibility by in vitro test of cytotoxicity by using the technique of neutral red incorporation. In the gel fraction test, both the PVP and PVA hydrogel showed a high crosslinking degree. The PVP hydrogel showed a greater percentage of swelling in relation to PVA and the cytotoxicity test of the hydrogels showed non-toxicity effect. The cytostimulation property of Arct\'Alg® was verified by the cytostimulation test with rabbit skin cells, it was showed an increase at about 50% of the cells when in contact with 0,5% of active agent. The hydrogel membranes prepared with 3% of Arct\'Alg® were subjected to the release test in an incubator at 37°C and aliquots collected during the test were quantified by high performance liquid chromatography (HPLC). The results obtained in the kinetics of release showed that the PVP hydrogel membranes released about 50% of Arct\'Alg® incorporated and the PVA hydrogel membranes at about 30%. In the cytostimulation test of released Arct\'Alg®, the PVP device showed an increase at about 80% of cell population in relation of test control, showing to be the greater device to be used in processes of skin repair.

Sistemas de liberação controlada vêm sendo cada vez mais utilizados em diferentes áreas tendo em vista sua aplicabilidade que os tornam uma tecnologia capaz de atender as necessidades econômicas e ambientais uma vez que permitem a utilização de princípios ativos em quantidades precisas e apenas nos locais desejados. Dentre a diversidade de opções de matrizes utilizadas nesses sistemas o poli(álcool vinílico) tem sido bastante empregado e pode ser obtido pela técnica de ciclos térmicos. Azadiractina, um princípio ativo encontrado em óleo de semente de Nim tem sido descrita como repelente de diferentes tipos de insetos e apresenta grande aplicabilidade na agricultura. Com base nas propriedades desse composto, propôs-se o desenvolvimento de um sistema de liberação controlada para combate a pulgas Ctenocephalides felis felis. No presente trabalho, foram realizadas caracterizações físico-químicas das matrizes e dispositivos através de ensaios de fração gel, intumescimento, calorimetria exploratória diferencial e microscopia eletrônica de varredura e caracterizações biológicas quanto à citotoxicidade do óleo de Nim, matrizes e dispositivos e bioensaio para análise do comportamento das pulgas na presença do óleo de Nim. As caracterizações físico-químicas permitiram a escolha da matriz mais adequada para o desenvolvimento do dispositivo. As caracterizações biológicas demonstraram ausência de citotoxicidade do óleo de Nim, das matrizes e dos dispositivos e o bioensaio resultou em 40% de mortalidade das pulgas testadas. Na cinética de liberação, verificou-se que todos os agentes encapsulantes utilizados permitiram a liberação de princípios ativos do óleo de Nim. / Controlled release systems has been increasingly used into different purposes due to its applicability that turns it onto a technology able to supply economic and environmental needs, once thats allows using precise amounts of active ingredients and only on aimed locations. Among the variety of matrix options used in this systems, poly (vinyl alcohol) has been larged employed and can be obtained by thermal cycles technics. Azadirachtin, an active ingredient found in Neem seed oil has been described as a repellent of different kinds of insects and has great agriculture\'s applicability. Based on compound properties, was proposed to develop a controlled release system to combat flea Ctenocephalides felis felis. In the present study was performed physicochemical characterizations of matrix and devices through gel fraction, swelling tests, differential scanning calorimetry, scanning electron microscopy and biological characterizations by cytotoxicity assay of Neen\'s oil, matrix and devices and analysis of flea\'s behavior at neem\'s oil presence by bioassay. The physical-chemical characterizations has enabled to choose the most suitable matrix to device\'s development. The biological characterizations has been demonstrated absence of oil\'s cytotoxicity, matrices and devices and bioassay has resulted in 40% mortality of fleas. On kinetic\'s release, was cheked that all used encapsulating agents has allowed the release neem\'s oil active principles.