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Vibro-acoustic products from re-cycled raw materials using a cold extrusion process : a continuous cold extrusion process has been developed to tailor a porous structure from polymeric waste, so that the final material possesses particular vibro-acoustic propertiesKhan, Amir January 2008 (has links)
A cold extrusion process has been developed to tailor a porous structure from polymeric waste. The use of an extruder to manufacture acoustic materials from recycled waste is a novel idea and the author is not aware of any similar attempts. The extruder conveys and mixes the particulates with a reacting binder. The end result is the continuous production of bound particulates through which a controlled amount of carbon dioxide gas that is evolved during the reaction is used to give the desired acoustic properties. The cold extrusion process is a low energy consuming process that reprocesses the post manufacturing waste into new vibro-acoustic products that can be used to meet the growing public expectations for a quieter environment. The acoustical properties of the developed products are modelled using Pade approximation and Johnson-Champoux-Allard models. Applications for the developed products are widespread and include acoustic underlay, insulation and panels in buildings, noise barriers for motorways and railway tracks, acoustic insulation in commercial appliances and transport vehicles.
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Preparação por inkjet e caracterização de dosímetros poliméricos para radiação UV-azul. / Fabrication using inkjet and characterization of polymer radiation dosimeter for UV-blue.Santos, Helton Almeida dos 26 May 2008 (has links)
Ao final da década de 1980, pesquisadores da empresa Eastman Kodak anunciaram as propriedades eletroluminescentes de materiais orgânicos não poliméricos. Seguindo essa linha, em 1990, um grupo de pesquisadores ingleses demonstrou propriedades semelhantes para os polímeros, utilizando-os como elementos ativos de dispositivos emissores de luz. Era este o início de uma nova área de pesquisa que tinha interface na eletrônica e nos novos semicondutores poliméricos. Surgiram os chamados polímeros luminescentes - resultado das descobertas das propriedades semicondutoras dos polímeros e copolímeros, blendas e heteroestruturas orgânico-inorgânicas. Os materiais semicondutores poliméricos apresentam diversas vantagens associadas à sua característica de fácil processamento e baixo custo de produção. Podem ser utilizados na forma de filmes finos que têm boas propriedades mecânicas e que permitem a sua utilização em substratos flexíveis. Diversas empresas como Philips, Sony, Pioneer, DuPont, Kodak e Uniax têm investido fortemente em pesquisa e desenvolvimento de dispositivos eletroluminescentes, memórias, sensores de imagem e outros sensores que aproveitam as propriedades dos polímeros semicondutores. A radiação, numa variada faixa de comprimentos de onda, pode afetar as propriedades de alguns desses polímeros semicondutores. A característica de material semicondutor, inerente a esses materiais, pode ser degradada por efeito de foto-oxidação que pode ser estimulado pela exposição à radiação. Surge a possibilidade de desenvolver dispositivos baseados em polímeros semicondutores para uso em detectores de radiação. Este trabalho consiste num estudo de desenvolvimento de dosímetros poliméricos de radiação para a faixa de comprimento de onda entre 400 nm e 500 nm, especificamente usada em ambientes hospitalares no tratamento intensivo de neonatos. Com o objetivo descrito, foi realizado o estudo de substratos adequados para a finalidade desejada, o desenvolvimento de um processo de deposição para os dispositivos de filmes-finos e o estudo da influência da radiação na faixa do ultravioleta-visível (UV-Vis) em suas propriedades. Das diversas técnicas de deposição de filmes finos existentes, foi selecionada para este estudo, a de deposição por jato de tinta (\"inkjet printing\") devido às suas características de simplicidade, potencial custo baixo e, principalmente, o menor nível de perda do polímero a ser depositado, já que a referida técnica permite a deposição de quantidades mínimas do material. Como material ativo foi selecionado um semicondutor polimérico da família dos polifluorenos, devido ao seu relativamente fácil manuseio. Pesquisadores da área, cada vez mais, acreditam que a impressão por jato de tinta seja uma das técnicas de deposição mais promissoras para a produção em grande escala. O objetivo desta pesquisa é contribuir com um novo instrumento a ser usado no monitoramento da irradiação no tratamento fototerápico da hiperbilirrubinemia no ambiente da neonatologia hospitalar. Atualmente os bebês recém-nascidos são tratados com empirismo considerável tendo em conta não haver procedimentos de controle para a dose da irradiação aplicada ao neonato nas incubadora neonatal das maternidades. Os riscos de hiperbilirrubinemia severa do neonato incluem a possibilidade de surdez, de paralisia cerebral ou mesmo de lesão cerebral em casos extremos. A observada Icterícia pode estar ligada à imaturidade do fígado do bebê. A bilirubinemia é muito freqüente em neonatos e precisa ser tratada para a redução dos citados riscos. O tratamento mais comum é a fototerapia com radiação na faixa do UV-próximo/azul. A fototerapia é realizada por várias sessões de muitas horas que dependem do nível de hiperbilirrubinemia no sangue, TBS (Total Bilirrubine Serum) do bebê. A hiperbilirrubinemia é crítica quando seu nível for igual ou maior que 428 micromol/litro ou 25 mg/dL (Referencia - Previsão e prevenção de hiperbilirrubinemia de neonatal extremo, T.B., Newman et al., Arco Pediatr Adolesc Med/Vol 154, Nov. 2000 pp 1140-1147). Além de permitir reduzir o empirismo do tratamento com o uso de um dosímetro para a faixa de radiação em tela, este pode ser usado para avaliar a condição da fonte de radiação específica de luz usada neste tipo de tratamento. O dosímetro proposto, como instrumento adicional para os neonatologistas poderá monitorar as doses de radiação aplicada durante a fototerapia e evitar excessos, reduzindo o tempo no protocolo de tratamento neonatal. / At the end of the 1980s, researchers from Eastman Kodak announced the electroluminescent properties of non-polymeric organic materials. At the beginning of the 1990s, researchers from the UK showed similar properties of organic polymers, using them as active elements in light emitting devices. It was the beginning of a new research area interfacing the electronics and the new polymeric semiconductors. As a result of the findings on the semiconducting properties of polymers and copolymers, blends and organic-inorganic heterostructures, a new class of materials became the research subject of several groups. Polymer semiconductors exhibit several advantages like simple processing and low production cost. They can be utilized as thin-films with good mechanical properties for use in flexible substrates. Several high-tech enterprises like Philips, Sony, Pioneer, DuPont, Kodak and Uniax are investing strongly in the research and development of such materials and devices, including memories, image sensors, light-emmiting devices, among others. Radiation in a very broad range of wavelengths can affect characteristics of some semiconductor polymers. Their inherent semiconducting feature can be degraded by the photo-oxidation effect, activated by radiation exposition. This suggests the possibility of the development of semiconductor polymer based radiation sensing devices. This work deals with a study of radiation dosimeters for the wavelength range of 400 nm to 500 nm, specifically important at the maternity hospitals in the therapy of newborn babies. To cope with this objective, the study of adequate substrates, development of suitable deposition process for the thin-film devices and study of its properties changes with radiation in the ultraviolet-visible (UV-Vis) range was done. From the different thin-film deposition techniques, the inkjet deposition technique was selected for this study thanks to its production simplicity, potential low cost an, mainly, because it permits the deposition of minute amounts of material, leading to very little material losses. As the active material a polymeric semiconductor of the fluorene family was selected thanks to its easy processing. Researchers of this area, more and more, believe that the Inkjet Printing is one of the very promising deposition techniques for mass production of those devices. The aim of this research is to offer a new tool to be used in the monitor of the irradiation in the phototherapy for severe hyperbilirubinemia of newborn babies. In most cases newborn babies are treated with a considerably empiric protocol considering the inexistence of procedures to control the radiation doses in the treatments. The risks of extreme neonatal hyperbilirubinemia include possibility of deafness, cerebral palsy or brain damage in extreme cases. Jaundice may be due to the immaturity of baby\'s liver. Bilirubinemia is most frequent in newborn and must be treated to reduce such risks. The most common treatment is phototherapy with nearUV-blue radiation. Phototherapy is accomplished by several sessions of many hours depending on the Total Bilirubin Serum (TBS) found in the baby blood. Hyperbilirubinemia is very dangerous to the near-term newborn when its level is equal or greater than 428 micromol/liter or 25 mg/dL (Reference Prediction and prevention of extreme neonatal hyperbilirubinemia, T.B., Newman et al., Arch Pediatr Adolesc Med/Vol 154, Nov. 2000 pp 1140-1147). Besides reducing the empiric treatments based on the nearUV-blue radiation, the use of a sensor can be important to evaluate the condition of the specific type of lamp used in the treatments. The proposed dosimeter can be an additional instrument for the neonatologists to be used in the determination of the phototherapy radiation dose, thus reducing, in the medical protocol, the jaundice treatment time.
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Optimization of pneumatic activity sensor : Development of a low friction seal / Optimering av pneumatisk aktivitetssensor : Framtagning av en lågfriktionstätningNilsson, Rickard January 2019 (has links)
In this thesis, the development of a new type of seal is presented along with the steps taken to attain the conclusive design. The results are presented in this paper as a cross-sectioned CAD-model along with the selection of materials and suggestions for future work. The project was commissioned by the multi-discipline engineering consultancy company Projektengagemang AB in Karlstad, Sweden, and carried out as a master’s thesis at Karlstad University. The commission was due to a demand for a new type of sealing solution, as friction is a problem within the field of micro-pneumatics. The work done consists of a study of different low-friction materials where a 30/70 PTFE/PEEK compound was selected as it displayed promising friction and wear properties. The material was then implemented into a design concluded by employing a product development process. The result rendered a prototype for a new kind of low-friction seal which uses the fluid pressure to achieve a sealing contact load between a piston/rod and the seal, which also was the goal set to achieve at the start of the project. Additionally, a design of experiments study was conducted to settle what design parameters were significant with respect to the contact load. For proceeding, making the concept a product ready for production, additional work is needed in the form of experimental material testing, development of a leakage model to optimize the contact load, determination of temperature and creep behaviour, as well as sufficient field testing. Lastly, a die tool must be designed for manufacturing with injection moulding as well as determining if any further processing is required. / Detta arbete behandlar utvecklingen av en ny sorts tätning samt arbetet som utförts för att nå en slutlig design. Resultaten presenteras i form av en CAD-modell tillsammans med materialval och förslag till fortsatta studier. Projektet utfördes efter förfrågan av konsultconcernen Projektengagemang AB i Karlstad, Sverige och utfördes som ett examensarbete för civilingenjörsexamen i maskinteknik vid Karlstads universitet. Detta gjordes eftersom det finns en efterfrågan på lågfriktionstätningar inom mikropneumatik där friktion är ett rådande problem. Arbetet består av en studie över att antal lågfriktionsmaterial där en komposit med 30/70 PTFE/PEEK valdes på grund av dess lovande nötnings- och friktionsegenskaper. Materialet implementerades sedan i design som togs fram genom en produktutvecklingsprocess. Resultatet är en prototyp för en ny sorts lågfriktionstätning som utnyttjar fluidtryck för att uppnå en tätande effekt mellan tätning och kolv vilket även var målsättningen för projektet. Flerfaktorförsök har under processen utnyttjats för att hitta vilka geometriska parametrar som påverkar kontaktkraften mellan tätning och motliggande yta. För att ta konceptet till en färdig produkt krävs fortsatt arbete innehållande experimentella materialtester, framtagning av en läckagemodell att optimera kontaktkraften mot, studier kring temperatur- och krypberoende samt fälttester för att verifiera funktionen över tid. Slutligen behöver ett verktyg för formsprutning tas fram tillsammans med eventuell ytterligare bearbetning för slutlig tillverkning av produkten.
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Maîtrise des interfaces pour le contrôle de l'injection de charges dans les polymères isolants électriques / Interface tailoring for charge injection control in electrically insulating polymersMillière, Laurent 15 December 2015 (has links)
Le phénomène d'injection de charges dans des isolants synthétiques et la distorsion du champ électrique qui en découlent représentent un frein au développement des câbles pour le transport d'énergie électrique sous haute tension continue (HVDC). Les solutions au problème sont le plus souvent recherchées en influant sur la formulation des matériaux, en l'occurrence le polyéthylène. La voie explorée dans cette thèse est une alternative consistant à créer une barrière permettant le contrôle de l'injection de charges dans un film de polyéthylène basse densité (LDPE) sous contrainte électrique. La solution proposée et étudiée consiste à modifier la surface du film polymère en y insérant des nanoparticules métalliques, susceptibles de jouer le rôle de pièges profonds et d'écranter le champ électrique, contrôlant ainsi l'injection. Pour cela, des nanoparticules d'argent (NPs d'Ag) sont déposées et recouvertes d'une matrice semi-isolante organosiliciée de type SiOxCy:H. La couche mince nanocomposite est élaborée par procédé plasma. Son épaisseur totale est d'environ 50 nm. Les nanoparticules sont obtenues par pulvérisation cathodique et la matrice environnante est réalisée avec un dépôt chimique en phase vapeur assisté par plasma. Le procédé d'élaboration est mis en œuvre dans le même réacteur en utilisant une décharge asymétrique RF à couplage capacitif entretenue à 13.56 MHz à basse pression du gaz. Une étude de l'influence des conditions opératoires du plasma sur les caractéristiques des NPs d'Ag et sur la matrice environnante a été réalisée. Les caractéristiques définies des NPs d'Ag sont la densité, la taille moyenne et la dispersion des nanoparticules. Les analyses physico-chimiques et structurales de la couche nanocomposite ont permis de valider la maîtrise de la formation des nanoparticules et de ses propriétés. L'évaluation de l'efficacité du dépôt a permis de définir les caractéristiques essentielles pour un contrôle des phénomènes d'injection de charges. Les analyses du comportement de l'ensemble étudié sous contrainte électrique ont été obtenues par des mesures de distribution de charges d'espace par méthode électroacoustique, de courant et de potentiel de surface. Les résultats montrent que la modification de la surface d'un film polymère par une couche mince nanocomposite contenant des NPs d'Ag enterrées à une profondeur contrôlée de la surface de la matrice organosiliciée permet le contrôle parfait de l'injection de charge dans un film de LPDE sous des niveaux de champ électrique usuels pour les applications HVDC. L'impact des caractéristiques de la couche nanocomposite sur l'efficacité du procédé a été évalué. Cette étude prouve le concept et ouvre la voie de la maîtrise des interfaces pour le contrôle de l'injection de charges dans des isolants polymères. / Charge injection phenomenon in electrically insulating polymers and the resultant electric field distortion remain obstacles to the development of cables for electrical energy transport under high voltage direct current (HVDC). Routes to solve the problem are most often looked for by acting on the material formulation, polyethylene in the present case. As alternative route, we explore in this thesis the possibility to develop a barrier layer allowing fine control of the charge injection in low density polyethylene (LDPE) films. The proposed and further studied solution is to tailor the surface of the polymer film by introducing metallic nanoparticles that would act as deep traps and would produce field screening, thus controlling charge injection. To achieve this, silver nanoparticles (AgNPs) are deposited on the LDPE and covered by a thin organosilicon layers of the type SiOxCy:H. The nanocomposite layer with total thickness of about 50 nm is elaborated in a plasma process. The AgNPs are obtained by sputtering of a silver target and the organosilicon matrix is then deposited in a plasma enhanced chemical vapor deposition (PECVD). The deposition process is realized in the same reactor in the plasma of an asymmetric RF capacitively coupled discharge maintained at 13.56 MHz at low gas pressure. The obtained characteristics for the AgNPs are for their mean size, density and dispersion. The physico-chemical and structural analyses of the nanocomposite layer allowed identifying the plasma operating conditions to control the AgNPs properties. From the evaluation of the efficiency of the AgNPs/organosilicon stack against charge injection, a detailed description of the required properties of the nanocomposite layer for the control of the charge injection phenomenon was derived. The behaviour of the studied structure, nanocomposite layer deposited on the surface of LDPE film, under electrical stress was studied by space charge measurement through the Pulsed Electro-Acoustic (PEA) method, current and surface potential decay measurements. The obtained results show that tailoring the surface of polyethylene film by very thin nanocomposite layer containing AgNPs embedded at a controlled distance from the free surface of the organosilicon matrix permits suppression of charges injection in LDPE films. The impact of nanocomposite layer structure on the efficiency of the barrier effect was evaluated. The mitigation effect is observed up to the typical service electric field for HVDC applications. This study presents a proof-of-concept and opens the way for interface tailoring to control the charge injection in electrically insulating polymers.
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Otimização do processo de injeção de cabedais monocolores em policloreto de vinila (PVC) :Estudo de caso: a indústria calçadista.MEDEIROS, Alexsander de Sousa. 24 April 2018 (has links)
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Previous issue date: 2015-05-29 / A alta reciclabilidade de materiais plásticos tem impulsionado cada vez mais a formação de produtos à base de reciclados, oque tem se tornado uma alternativa “eco sustentável” e de baixo custo para as empresas que beneficiam plásticos. Neste sentido, este trabalho objetiva estudar o processo de injeção de cabedais monocolores em PVC, numa indústria do ramo calçadista, produzidos com adição de mistura reciclada através de processo convencional (injeção direta em máquina horizontal), afim de se obter a melhor parametrização para um modelo específico, com foco na obtenção de peças com qualidade e propriedades mecânicas similares as injetados com PVC virgem. Utilizou-se de ferramentas de simulação numérica (CFD), técnicas experimentais e ensaios mecânicos de dureza, microscopia óptica, tração (não normatizados). Observou-se que para o modelo em estudo (cabedal Summer), parâmetros como a temperatura do material, pressão (injeção, recalque e contra pressão) e velocidade de injeção do material no molde, ocasionam interferências e problemas na moldagem das peças, gerando produtos de baixa qualidade. As simulações através de software comprovaram os resultados obtidos nos experimentos gerados pela matriz experimental, apontando os parâmetros ideais para a produção do modelo em questão, considerando as mesmas condições operacionais. Os ensaios realizados apontaram que as propriedades mecânicas foram pouco afetadas pela adição de material reciclado, sendo possível a produção em escala industrial de cabedais monocolores (preto), utilizando-se material reprocessado (1 ciclo), sem alteração significativa nas características mecânicas, visuais e de conforto. / The high recyclability of plastic materials has increasingly driven the formation of recycledbased products, which has become an eco-sustainable and cost-effective alternative for companies use plastics as now materials. This work aims at investigating the monochromatic uppers injection process in PVC, at an footwear industry, produced from the addition of recycled mixture through the conventional process (direct injection in horizontal machine), in order to obtain the best parameter for a specific model, focusing on obtaining pieces with similar quality and mechanical properties to those injected with virgin PVC. In the methodological part, numerical simulation tools (CFD), experimental techniques and (not standardized) mechanical tests (hardness test, optical microcopy, tension) were used. It was observed that for the focused model, parameters such as material temperature, pressure (injection, discharge and counter pressure) and mass flow rate of injection in the mold, led to interference and problems in molding the parts, resulting in products with low quality. Simulations using software confirmed the results obtained from the experiments generated by the experimental matrix, showing the ideal parameters to produce the modelselected, at the same operational conditions. The performed tests revealed that the mechanical properties were little affected by the addition of recycled material, making possible the production of monochromatic (black) uppers in industrial scale, using reprocessed material (1 cycle) with no significant changes of mechanical, visual and comfort features of the product.
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New saloplastic biomaterials based on ultracentrifuged polyelectrolyte complexes / Nouveaux biomatériaux saloplastiques basés sur des complexes de polyélectrolytes ultracentrifugésTirado Viloria, Patricia Carolina 18 September 2012 (has links)
Ce travail avait pour but de développer un nouveau type de matériaux basés sur des complexes polyelectrolytes. Ces matériaux ont été obtenus par l’ultracentrifugation des complexes soit d’origine naturelle ou soit d’origine synthétique. Le système de polyélectrolytes ainsi que les conditions dans lesquelles ces matériaux peuvent être obtenus, suivi par le choix du système optimal pour des études complémentaires ont été décrits. PAA / PAH CoPECs a été choisi comme systèmes modèles de synthèse et ses propriétés physico chimiques (composition, structure et les propriétés mécaniques) ont été décrits ici en détails. Nous avons montré que les propriétés de la composition, la structure et mécanique de le PAA/PAH CoPECs peut être contrôlée en modifiant les conditions d’assemblage (pH, concentration des polyélectrolytes, [NaCl], la vitesse et la commande de l’addition). Également, les conditions environnementales ([NaCl] et pH) ont également été utilisés pour contrôler la taille des pores et porosité des PAA/PAH CoPECs . Enfin, leur capacité à servir de support pour l’immobilisation d’enzymes a également été étudiée. Nous avons optimise les conditions d’assemblage afin de maintenir le maximum quantité de l’enzyme dans le complexe. Nous avons également démontré que CoPECs fournit la stabilisation à long terme, ainsi que la protection de l’enzyme à des températures élevées. Ainsi, PAA / PAH CoPECs sont des candidats potentiels pour être utilisé comme des supports pour l’ingénierie tissulaire et pour l’immobilisation d’enzymes. / This work was aimed to the develop of a new kind of materials of polyelectrolytes complexes. These materials were obtained by the ultracentrifugation of complexes either of natural or synthetic origin. The polyelectrolytes systems as well as the conditions under which these materials could be obtained, followed by the selection of the optimal system to further studies was described. PAA/PAH CoPECs was chosen as synthetic model systems and its physiochemical properties (composition, structure and mechanical properties) were here deeply described. We demonstrated that the composition, structure and mechanical properties can be controlled by changing the assembly conditions (pH, concentration of the polyelectrolytes, [NaCl], speed and order of addition). Moreover, the environmental conditions ([NaCl] and pH) were also used to control the porosity and pores size of the PAA/PAH CoPECs. Finally their ability to serve as scaffold for enzyme immobilization was also studied. We optimized the assembly conditions to keep the maximum of the activity. We also demonstrated that the CoPECs structure provides the stabilization in long term as well as the protection of the enzyme from high temperature. Thus, PAA/PAH CoPECs is a potential and suitable candidates as scaffold for tissue engineering and for the immobilization of enzymes.
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Preparação por inkjet e caracterização de dosímetros poliméricos para radiação UV-azul. / Fabrication using inkjet and characterization of polymer radiation dosimeter for UV-blue.Helton Almeida dos Santos 26 May 2008 (has links)
Ao final da década de 1980, pesquisadores da empresa Eastman Kodak anunciaram as propriedades eletroluminescentes de materiais orgânicos não poliméricos. Seguindo essa linha, em 1990, um grupo de pesquisadores ingleses demonstrou propriedades semelhantes para os polímeros, utilizando-os como elementos ativos de dispositivos emissores de luz. Era este o início de uma nova área de pesquisa que tinha interface na eletrônica e nos novos semicondutores poliméricos. Surgiram os chamados polímeros luminescentes - resultado das descobertas das propriedades semicondutoras dos polímeros e copolímeros, blendas e heteroestruturas orgânico-inorgânicas. Os materiais semicondutores poliméricos apresentam diversas vantagens associadas à sua característica de fácil processamento e baixo custo de produção. Podem ser utilizados na forma de filmes finos que têm boas propriedades mecânicas e que permitem a sua utilização em substratos flexíveis. Diversas empresas como Philips, Sony, Pioneer, DuPont, Kodak e Uniax têm investido fortemente em pesquisa e desenvolvimento de dispositivos eletroluminescentes, memórias, sensores de imagem e outros sensores que aproveitam as propriedades dos polímeros semicondutores. A radiação, numa variada faixa de comprimentos de onda, pode afetar as propriedades de alguns desses polímeros semicondutores. A característica de material semicondutor, inerente a esses materiais, pode ser degradada por efeito de foto-oxidação que pode ser estimulado pela exposição à radiação. Surge a possibilidade de desenvolver dispositivos baseados em polímeros semicondutores para uso em detectores de radiação. Este trabalho consiste num estudo de desenvolvimento de dosímetros poliméricos de radiação para a faixa de comprimento de onda entre 400 nm e 500 nm, especificamente usada em ambientes hospitalares no tratamento intensivo de neonatos. Com o objetivo descrito, foi realizado o estudo de substratos adequados para a finalidade desejada, o desenvolvimento de um processo de deposição para os dispositivos de filmes-finos e o estudo da influência da radiação na faixa do ultravioleta-visível (UV-Vis) em suas propriedades. Das diversas técnicas de deposição de filmes finos existentes, foi selecionada para este estudo, a de deposição por jato de tinta (\"inkjet printing\") devido às suas características de simplicidade, potencial custo baixo e, principalmente, o menor nível de perda do polímero a ser depositado, já que a referida técnica permite a deposição de quantidades mínimas do material. Como material ativo foi selecionado um semicondutor polimérico da família dos polifluorenos, devido ao seu relativamente fácil manuseio. Pesquisadores da área, cada vez mais, acreditam que a impressão por jato de tinta seja uma das técnicas de deposição mais promissoras para a produção em grande escala. O objetivo desta pesquisa é contribuir com um novo instrumento a ser usado no monitoramento da irradiação no tratamento fototerápico da hiperbilirrubinemia no ambiente da neonatologia hospitalar. Atualmente os bebês recém-nascidos são tratados com empirismo considerável tendo em conta não haver procedimentos de controle para a dose da irradiação aplicada ao neonato nas incubadora neonatal das maternidades. Os riscos de hiperbilirrubinemia severa do neonato incluem a possibilidade de surdez, de paralisia cerebral ou mesmo de lesão cerebral em casos extremos. A observada Icterícia pode estar ligada à imaturidade do fígado do bebê. A bilirubinemia é muito freqüente em neonatos e precisa ser tratada para a redução dos citados riscos. O tratamento mais comum é a fototerapia com radiação na faixa do UV-próximo/azul. A fototerapia é realizada por várias sessões de muitas horas que dependem do nível de hiperbilirrubinemia no sangue, TBS (Total Bilirrubine Serum) do bebê. A hiperbilirrubinemia é crítica quando seu nível for igual ou maior que 428 micromol/litro ou 25 mg/dL (Referencia - Previsão e prevenção de hiperbilirrubinemia de neonatal extremo, T.B., Newman et al., Arco Pediatr Adolesc Med/Vol 154, Nov. 2000 pp 1140-1147). Além de permitir reduzir o empirismo do tratamento com o uso de um dosímetro para a faixa de radiação em tela, este pode ser usado para avaliar a condição da fonte de radiação específica de luz usada neste tipo de tratamento. O dosímetro proposto, como instrumento adicional para os neonatologistas poderá monitorar as doses de radiação aplicada durante a fototerapia e evitar excessos, reduzindo o tempo no protocolo de tratamento neonatal. / At the end of the 1980s, researchers from Eastman Kodak announced the electroluminescent properties of non-polymeric organic materials. At the beginning of the 1990s, researchers from the UK showed similar properties of organic polymers, using them as active elements in light emitting devices. It was the beginning of a new research area interfacing the electronics and the new polymeric semiconductors. As a result of the findings on the semiconducting properties of polymers and copolymers, blends and organic-inorganic heterostructures, a new class of materials became the research subject of several groups. Polymer semiconductors exhibit several advantages like simple processing and low production cost. They can be utilized as thin-films with good mechanical properties for use in flexible substrates. Several high-tech enterprises like Philips, Sony, Pioneer, DuPont, Kodak and Uniax are investing strongly in the research and development of such materials and devices, including memories, image sensors, light-emmiting devices, among others. Radiation in a very broad range of wavelengths can affect characteristics of some semiconductor polymers. Their inherent semiconducting feature can be degraded by the photo-oxidation effect, activated by radiation exposition. This suggests the possibility of the development of semiconductor polymer based radiation sensing devices. This work deals with a study of radiation dosimeters for the wavelength range of 400 nm to 500 nm, specifically important at the maternity hospitals in the therapy of newborn babies. To cope with this objective, the study of adequate substrates, development of suitable deposition process for the thin-film devices and study of its properties changes with radiation in the ultraviolet-visible (UV-Vis) range was done. From the different thin-film deposition techniques, the inkjet deposition technique was selected for this study thanks to its production simplicity, potential low cost an, mainly, because it permits the deposition of minute amounts of material, leading to very little material losses. As the active material a polymeric semiconductor of the fluorene family was selected thanks to its easy processing. Researchers of this area, more and more, believe that the Inkjet Printing is one of the very promising deposition techniques for mass production of those devices. The aim of this research is to offer a new tool to be used in the monitor of the irradiation in the phototherapy for severe hyperbilirubinemia of newborn babies. In most cases newborn babies are treated with a considerably empiric protocol considering the inexistence of procedures to control the radiation doses in the treatments. The risks of extreme neonatal hyperbilirubinemia include possibility of deafness, cerebral palsy or brain damage in extreme cases. Jaundice may be due to the immaturity of baby\'s liver. Bilirubinemia is most frequent in newborn and must be treated to reduce such risks. The most common treatment is phototherapy with nearUV-blue radiation. Phototherapy is accomplished by several sessions of many hours depending on the Total Bilirubin Serum (TBS) found in the baby blood. Hyperbilirubinemia is very dangerous to the near-term newborn when its level is equal or greater than 428 micromol/liter or 25 mg/dL (Reference Prediction and prevention of extreme neonatal hyperbilirubinemia, T.B., Newman et al., Arch Pediatr Adolesc Med/Vol 154, Nov. 2000 pp 1140-1147). Besides reducing the empiric treatments based on the nearUV-blue radiation, the use of a sensor can be important to evaluate the condition of the specific type of lamp used in the treatments. The proposed dosimeter can be an additional instrument for the neonatologists to be used in the determination of the phototherapy radiation dose, thus reducing, in the medical protocol, the jaundice treatment time.
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Eco-designed functionalization of polyester fabricAgnhage, Tove January 2017 (has links)
There is an increased awareness of the textile dyeing and finishing sector’s high impact on the environment due to high water consumption, polluted wastewater, and inefficient use of energy. To reduce environmental impacts, researchers propose the use of dyes from natural sources. The purpose of using these is to impart new attributes to textiles without compromising on environmental sustainability. The attributes given to the textile can be color and/or other characteristics. A drawback however, is that the use of bio-sourced dyes is not free from environmental concerns. Thus, it becomes paramount to assess the environmental impacts from using them and improve the environmental profile, but studies on this topic are generally absent. The research presented in this thesis has included environmental impact assessment, using the life cycle assessment (LCA) tool, in the design process of a multifunctional polyester (PET) fabric using natural anthraquinones. By doing so an eco-design approach has been applied, with the intention to pave the way towards eco-sustainable bio-functionalization of textiles. The anthraquinones were obtained from the root extracts of the madder plant (Rubia tinctorum L.), referred to as madder dye. The research questions were therefore formulated related to the use of madder dye. Three research questions have been answered: (I) Can madder dye serve as a multifunctional species onto a PET woven fabric? (II) How does the environmental profile of the dyeing process of PET with madder dye look like, and how can it be improved? (III) What are the main challenges in using LCA to assess the environmental impacts of textile dyeing with plant-based dyes? It is concluded that there is a potential for the madder dye to serve as a multifunctional species onto PET. Based on the encouraging result, a recommendation for future work would be to focus on the durability of the functionalities presented and their improvement potential, both in exhaustion dyeing and pad-dyeing. LCA driven process optimization of the exhaustion dyeing enabled improvement in every impact category studied. However, several challenges have been identified which need to be overcome for the LCA to contribute to the sustainable use of multifunctional plant-based species in textile dyeing. The main challenges are the lack of available data at the research stage and the interdisciplinary nature of the research arena. It is envisaged that if these challenges are addressed, LCA can contribute towards sustainable bio-functionalization of textiles. / Le secteur de la teinture et de l’ennoblissement textile est de plus en plus conscient de son impact sur l’environnement dû principalement à la consommation élevée de l’eau et à sa pollution, et aux pertes d’énergie. Pour réduire ces impacts, les chercheurs proposent l’utilisation de molécules issues de ressources naturelles, pour traiter les textiles en limitant les impacts sur l’environnement. C’est le cas pour l’obtention de textiles colorés ou pour l’attribution de toute autre fonctionnalité. Cependant, il n’est pas évident que ces molécules bio-sourcées n’aient aucun impact sur l’environnement. On comprend l’importance d’évaluer les impacts de leur utilisation et d’améliorer leur profil environnemental. Or ce type d’étude est peu présent dans la littérature. La recherche présentée dans cette thèse comporte l’évaluation des impacts environnementaux en utilisant l’outil d’analyse du cycle de vie (ACV) pour la conception du traitement d’un tissu de polyester (PET) multifonctionnel avec des anthraquinones naturelles. La méthodologie d’éco conception que nous avons appliquée ouvre la voie à une bio-fonctionnalisation des textiles plus respectueuse de l’environnement. Les anthraquinones ont été obtenues par extraction des racines de plantes de garance et constituent le colorant appelé garance. Les trois questions principales abordées lors de ce travail de recherche sont formulées autour de l’utilisation de la garance : (I) Peut-on traiter les tissus de PET avec de la garance pour obtenir des propriétés multifonctionnelles ? (II) Quel est le profil environnemental du procédé de teinture du PET par la garance et comment l’améliorer ? (III) Quels sont les principaux challenges pour l’utilisation de l’ACV dans l’évaluation environnementale du traitement des textiles par des colorants naturels? Nous avons montré que la garance peut être utilisée pour conférer des propriétés multifonctionnelles au PET. Ensuite, nous avons pu orienter notre étude pour améliorer la durabilité des traitements par les procédés de fonctionnalisation à la fois par épuisement ou par foulardage. En s’appuyant sur l’ACV, l’optimisation de la teinture que nous avons réalisée réduit tous les impacts sur l’environnement. Cette étude nous permet d’identifier les challenges qui doivent être surmontés pour que l’ACV puisse contribuer à l’utilisation de bio-molécules pour la teinture des textiles dans le respect des principes de développement durable. Ils concernent le manque de données pour ces travaux de recherche et leur nature interdisciplinaire. Ainsi, en résolvant ces questions, on peut envisager aboutir à une bio- fonctionnalisation des textiles respectueuse de l’environnement. / Den höga miljöpåverkan från textilfärgning och efterbehandling, på grund av hög vattenförbrukning, dess förorening, och ineffektiv användning av energi, är idag välkänt. För att minska miljöpåverkan föreslår forskningsvärlden användning av färgämnen från naturliga resurser. Syftet med att använda dessa är att ge nya attribut till textilier utan att göra avkall på miljömässig hållbarhet. Attribut som ges kan vara färg och/eller andra egenskaper. En nackdel är dock att användningen av bio-baserade färgämnen är inte fri från att belasta miljön. Det blir därför av största betydelse att bedöma denna miljöpåverkan och förbättra miljöprofilen. Sådana studier är dock i allmänhet sällsynta. Studien som presenteras i denna avhandling har inkluderat miljöpåverkans- bedömning, med hjälp av livscykelanalys (LCA), i designprocessen av en multifunktionell polyester (PET) väv via naturliga antrakinoner. Genom att göra så har ett eko-design tillvägagångssätt använts, med avsikt att bana väg för miljömässigt hållbar bio-funktionalisering av textil. Antrakinonerna erhölls från rot extrakt av växten krapp (Rubia tinctorum L.), och hänvisas till som krapp färgämne. Frågeställningar var därför formulerade relaterat till användningen av krapp färgämne. Tre forskningsfrågor har besvarats: (I) Kan krapp färgämne verka multifunktionellt på en PET väv? (II) Hur ser miljöprofilen ut, från färgningsprocessen av PET med krapp färgämne, och hur kan den förbättras? (III) Vilka är de största utmaningarna med att använda LCA för att bedöma miljökonsekvenserna av textilfärgning med växtbaserade färgämnen? Det kan konkluderas att det finns potential för krapp färgämne att verka multifunktionellt på PET. Baserat på uppmuntrande resultat är en rekommendation för det framtida arbetet att fokusera på kvalitén hos de attribut som presenterats och deras förbättringspotential, både i färgning via färgbad och via foulard. LCA driven processoptimering av textilfärgningen förbättrade i varje miljöpåverkans- kategori som studerats. Emellertid har flera utmaningar identifierats som måste övervinnas för att LCA skall kunna bidra till en hållbar användning av multifunktionella växtbaserade färgämnen för textil. De största utmaningarna är bristen på tillgängliga data i forskningsstadiet och den tvärvetenskapliga forskningsarenan. Det är tänkt att om dessa utmaningar bemästras kan LCA bidra till en hållbar bio-funktionalisering av textil. / <p>Disputationen kan följas via länk i sal U401b, Textilhögskolan, Högskolan i Borås</p> / Erasmus Mundus Joint Doctorate program: Sustainable Management and Design for Textiles
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Bestämning av dynamiska moduler hos fluorgummi FKM 70–1. : En motodbeskrivning för dynamiska modulvärden.Johnsson, Emil, Hellgren, Elvira January 2020 (has links)
In order to quality assure and investigate material compositions in materials for components, safe methods need to be used to obtain correct results. When starting up a new analysis tool, a basic investigation is needed of how the tool is prepared, operated and how analysis data is interpreted. This is to maneuver the analysis tool correctly in the future work. Misuse of the analysis tool could potentially lead to the wrong material being selected for components and failure to respond to accident investigations. This thesis has been written at Husqvarna AB and its department Specialist Lab´s Material Laboratory. This study would lay the groundwork for how their new dynamic mechanical analysis tool should be used and operated to obtain correct material data for future analyzed materials. Dynamic mechanical analysis is a tool that has a wide range of application and Husqvarna's main purpose is to be able to analyze the dynamic mechanical properties of different polymers and rubber types. This study will primarily address an analysis of the dynamic properties of polyethylene FKM 70-1 in a DMA instrument. This is to carry out a successful analysis that can be used as a basis for future work in Husqvarna's DMA instrument.
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Washing and drying reusable sanitary padsSundberg, Fanny, Anderhell, Max January 2019 (has links)
Period poverty is a problem mainly found in places characterized by poverty. The lack of means for women and girls to properly handle their menstruation is the essence of the problem. With a lack of both quantity and quality regarding water often being an issue in such places, the hygiene is a constant challenge. Two different kinds of sanitary products are used globally, disposable and reusable. The reusable ones are often being made of cotton or other absorbent materials. Regardless the material, reusable products need cleaning between the times of use, which could be a challenge when water is not always accessible. To have a reusable sanitary pad that efficiently can be cleaned with low amounts of resources is important, especially in impoverished places. Spacerpad is a reusable sanitary pad and a part of a project at the University of Borås. The aim for the project is to reduce period poverty and to educate women and girls in menstrual hygiene management. The pad is made of polyester which does not absorb blood or water, instead the pad merely contains the fluids. This thesis was conducted as a field study in Nairobi, Kenya. The study aimed to simulate a menstruation, in order to analyze the microbial activity in two different reusable sanitary pads, during as well as after menstruation. With the influences from interviews and resources found in Kibera (a slum in Nairobi) a simulation of five days was executed, with nutrient solution instead of menstrual blood. The Spacerpad and a cotton pad were exposed to the same procedures and the effects of washing and drying were studied. The microbial activity was measured with the help of dipslides, a growth medium. The results of this study show that both Spacerpad and the cotton pad could be carriers of heavy growth of bacteria. Increasing microbial activity throughout the simulation as the days went by, ended with a dividing result after a soap wash as the final washing procedure. The pad made of cotton still carried above slight growth, compared to Spacerpad that showed almost no activity after the final cleanse. Even though the microbial activity reached high levels during the simulation, the fact that the Spacerpad can be cleaned with limited resources could be reason enough to consider the Spacerpad as a sufficiently sanitary product in an impoverished place like Kibera. / Mensfattigdom är något som vanligtvis återfinns på platser präglade av fattigdom. Bristen på medel för kvinnor och flickor att kunna hantera sin menstruation är kärnan av problemet. Med en brist i kvantitet och kvalitet på vatten som ett vanligt problem på sådana platser är det en konstant utmaning att upprätthålla sin hygien. Menstruationsskydd delas in i två olika typer, engångs- och återanvändningsbara produkter. De återanvändningsbara produkterna består ofta av bomull eller andra absorberande material. Oavsett material måste produkterna rengöras mellan användningarna, vilket kan vara en utmaning på platser där vatten inte alltid är tillgängligt. Tillgång till en återanvändningsbar binda som kan rengöras med små resurser är viktigt, speciellt på platser som kännetecknas av fattigdom. Spacerpad är en återanvändningsbar binda, framtagen som del av ett projekt vid Högskolan Borås, vars syfte är att reducera mensfattigdom och samtidigt utbilda kvinnor och flickor om menstruation och hygien. Bindan är tillverkad av polyester som inte absorberar blod eller vatten, vilket gör att bindan snarare håller vätskorna på plats. Denna uppsats gjordes som en fältstudie på plats i Nairobi, Kenya och hade som mål att simulera en menstruation. Detta för att se hur den mikrobiella aktiviteten skulle kunna se ut, under och efter en menstruation. Med influenser ur intervjuer och tillgångar från Kibera (ett slumområde i Nairobi) genomfördes simulationen med näringslösning som substitut till mensblod. I simulationen studerades effekten av tvätt och tork på den mikrobiella aktiviteten. Spacerpad och en bomullsbinda genomgick samma processer där aktiviteten mättes med hjälp av dipslides, ett växtmedium. Resultaten från denna studie visar att både Spacerpad och bomullsbindan kan vara bärare av hög tillväxt av bakterier. En ökande bakteriell aktivitet genom testdagarna, slutade med ett tudelat resultat efter en tvåltvätt som sista procedur. Bindan av bomull hade lätt tillväxt, medan Spacerpad knappt visade någon tillväxt alls efter den sista rengöringen. Den mikrobiella aktiviteten hos Spacerpad nådde höga nivåer under simulationen. Trots det så gör förmågan att kunna rengöras med låg åtgång av resurser, att den kan anses vara sanitär nog för att användas på platser präglade av fattigdom, som i Kibera.
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