Diploma thesis is focused on modification and characterization of polypropylene (PP) products surfaces by the chemical way. In theoretical part of thesis are summarized the current knowledge of this topic including characterization methods. Polypropylene surfaces were modified by acrylic monomers (acrylic acid, acrylic acid with 20 mol% content of sodium acrylate and acryl amide). Modified surfaces were characterized by infrared spectroscopy with ATR technique. The comparative parameter was carbonyl index determined from absorption peaks of functional methyl groups (2950 cm-1 ) and functional carbonyl groups (1700-1750 cm-1) of FTIR-ATR spectra. Determination of effect of initiator concentration on the modification process was done for acetophenone and benzophenone. There were determined the time dependence of carbonyl index for time from 0 to 600 s of mentioned monomers. In the same condition were modified test specimens designed for preparation of adhesive joints. Joints were bonded by cyanoacrylate adhesive that provide reaction with surface of polyacrylic acid. There were founded conditions of modification that provided strength of adhesive joints higher than strength of original PP. There were identified changes of surface roughness by using of confocal microscopy.

A produção de mel no Brasil tem aumentado consideravelmente e vem ganhando destaque no mercado internacional, consequentemente muitas exigências passaram a fazer parte da cadeia produtiva apícola. Além das análises previstas na legislação brasileira, o mercado externo procura produtos que atendam aos mais rigorosos padrões de qualidade. O mel possui características interessantes devido a sua constituição, porém, existem problemas que podem alterar seu padrão de identidade e qualidade. A aplicação da radiação gama é uma proposta viável que promove a diminuição da carga microbiana sem alterar a constituição e as características físico-químicas, com perdas nutricionais menores quando comparada a outros tratamentos usados em alimentos. Neste estudo, além dos parâmetros físico-químicos exigidos pela legislação brasileira (MAPA), também foram incluídas outras análises pertinentes, inclusive a técnica de espectroscopia no infravermelho com transformada de Fourier (FTIR-ATR). As análises microbiológicas foram realizadas nas amostras de méis puros, nas quais, posteriormente, foram inoculadas cargas microbianas conhecidas para avaliar a ação da radiação gama nas doses de 5 e 10 kGy. O teste triangular foi utilizado na análise sensorial para diferenciar as amostras não-irradiadas das irradiadas. As maiores modificações nas amostras de méis foram, principalmente, nas concentrações de HMF (hidroximetilfurfural) e na atividade diastásica, ocorrendo diminuição significativa em todas as amostras analisadas. Houve redução na carga microbiana a partir da aplicação da dose de 5 kGy, atingindo a ausência com a aplicação de 10 kGy de dose, com exceção do Paenibacillus larvae que mostrou ser mais resistente. A análise sensorial realizada nas amostras de mel e mel irradiado, com doses de 5, 10 e 15 kGy, apontou não haver diferença significativa (5%) entre as amostras controle e irradiadas. A aplicação da radiação gama em méis mostrou ser um método muito útil na descontaminação microbiológica, apresentando poucas alterações no produto com doses de até 10 kGy. / Honey production in Brazil has increased considerably and gaining proeminence on the international market, as a result many demands have become part of the productive honey chain. In addition to the analyses provided for the Brazilian legislation, international market demand products that meet the most stringent quality standards. Honey has interesting characteristics due to its constitution, but even so there are problems that can change some how your identity and quality. The application of gamma radiation is a viable proposal which promotes the reduction of bioburden without changing the constitution and most importantly the physicochemical properties, with smaller nutritional losses when compared to other treatments used in foods. This study beyond the physicochemical parameters required by Brazilian regulation also included other relevant analyses, including FT-IR ATR. Microbiological analyses were carried out on samples of pure honeys and subsequently inoculated microbial known loads to assess the action of gamma radiation in doses of 5 and 10 kGy. The triangular test was used to differentiate the irradiated and not irradiated. samples The major changes that have occurred in samples of honeys were mainly in concentrations of HMF (hydroxymethilfurfural) and diastase activity occurring a significant decrease in all analyzed samples. There was a reduction microbiological from the application of the 5 kGy, reaching absence with 10 kGy dose except Paenibacillus larvae. The sensory analysis conducted on samples of honey and honey irradiated with 5, 10 and 15 kGy doses, pointed out that there is no significant difference (5%) between irradiated and control samples. The application of gamma radiation in honeys proved a very useful method in microbiological decontamination, featuring few changes in the product at doses up to 10 kGy.

A produção de mel no Brasil tem aumentado consideravelmente e vem ganhando destaque no mercado internacional, consequentemente muitas exigências passaram a fazer parte da cadeia produtiva apícola. Além das análises previstas na legislação brasileira, o mercado externo procura produtos que atendam aos mais rigorosos padrões de qualidade. O mel possui características interessantes devido a sua constituição, porém, existem problemas que podem alterar seu padrão de identidade e qualidade. A aplicação da radiação gama é uma proposta viável que promove a diminuição da carga microbiana sem alterar a constituição e as características físico-químicas, com perdas nutricionais menores quando comparada a outros tratamentos usados em alimentos. Neste estudo, além dos parâmetros físico-químicos exigidos pela legislação brasileira (MAPA), também foram incluídas outras análises pertinentes, inclusive a técnica de espectroscopia no infravermelho com transformada de Fourier (FTIR-ATR). As análises microbiológicas foram realizadas nas amostras de méis puros, nas quais, posteriormente, foram inoculadas cargas microbianas conhecidas para avaliar a ação da radiação gama nas doses de 5 e 10 kGy. O teste triangular foi utilizado na análise sensorial para diferenciar as amostras não-irradiadas das irradiadas. As maiores modificações nas amostras de méis foram, principalmente, nas concentrações de HMF (hidroximetilfurfural) e na atividade diastásica, ocorrendo diminuição significativa em todas as amostras analisadas. Houve redução na carga microbiana a partir da aplicação da dose de 5 kGy, atingindo a ausência com a aplicação de 10 kGy de dose, com exceção do Paenibacillus larvae que mostrou ser mais resistente. A análise sensorial realizada nas amostras de mel e mel irradiado, com doses de 5, 10 e 15 kGy, apontou não haver diferença significativa (5%) entre as amostras controle e irradiadas. A aplicação da radiação gama em méis mostrou ser um método muito útil na descontaminação microbiológica, apresentando poucas alterações no produto com doses de até 10 kGy. / Honey production in Brazil has increased considerably and gaining proeminence on the international market, as a result many demands have become part of the productive honey chain. In addition to the analyses provided for the Brazilian legislation, international market demand products that meet the most stringent quality standards. Honey has interesting characteristics due to its constitution, but even so there are problems that can change some how your identity and quality. The application of gamma radiation is a viable proposal which promotes the reduction of bioburden without changing the constitution and most importantly the physicochemical properties, with smaller nutritional losses when compared to other treatments used in foods. This study beyond the physicochemical parameters required by Brazilian regulation also included other relevant analyses, including FT-IR ATR. Microbiological analyses were carried out on samples of pure honeys and subsequently inoculated microbial known loads to assess the action of gamma radiation in doses of 5 and 10 kGy. The triangular test was used to differentiate the irradiated and not irradiated. samples The major changes that have occurred in samples of honeys were mainly in concentrations of HMF (hydroxymethilfurfural) and diastase activity occurring a significant decrease in all analyzed samples. There was a reduction microbiological from the application of the 5 kGy, reaching absence with 10 kGy dose except Paenibacillus larvae. The sensory analysis conducted on samples of honey and honey irradiated with 5, 10 and 15 kGy doses, pointed out that there is no significant difference (5%) between irradiated and control samples. The application of gamma radiation in honeys proved a very useful method in microbiological decontamination, featuring few changes in the product at doses up to 10 kGy.

Expansive clay mineral contamination of road aggregate materials in Texas is a persistent problem. Hydrous layer silicate minerals - particularly smectites - in concretes are associated with decreased strength and durability in Portland cement and asphalt concretes. The Texas Department of Transportation (TXDOT) and Texas A&M Transportation Institute (TTI) evaluated the methylene blue adsorption test for its potential to identify and estimate quantities of expansive clays in aggregate stockpiles. Clay mineral quantification was completed for 27 geologically-diverse aggregate materials from Texas, Oklahoma, and Arkansas. X-ray diffraction analysis (XRD) of separated clays on glass was conducted, and NEWMOD was utilized to model the resulting diffraction patterns. Methylene blue adsorption (MBA) and cation exchange capacity (CEC) of clay fractions (< 2µm) and -40 mesh screenings (< 400 µm) were determined for most aggregates. Many of the aggregates exhibited significant quantities of expansive clay minerals such as smectite, which are linked to deleterious performance properties in concretes. While the majority of aggregates were derived from crushed limestone or calcareous river gravel parent materials, severalexhibited uncommon origins and unusual clay mineralogy. Due to the relatively low number of aggregates tested and diverse geological origins of the different aggregates,it proved difficult to formalize any conclusions abouttrendsbetweenthedifferent aggregate performance properties.

The accurate and safe diagnosis of breast cancer is a significant societal issue, with annual disease incidence of 48,000 women and around 370 men in the UK. Early diagnosis of the disease allows more conservative treatments and better patient outcomes. Microcalcifications in breast tissue are an important indicator for breast cancers, and often the only sign of their presence. Several studies have suggested that the type of calcification formed may act as a marker for malignancy and its presence may be of biological significance. In this work, breast calcifications are studied with FTIR, synchrotron FTIR, ATR FTIR, and Raman mapping to explore their disease specific composition. From a comparison between vibrational spectroscopy and routine staining procedures it becomes clear that calcium builds up prior to calcification formation. Raman and FTIR indicate the same size for calcifications and are in agreement with routine staining techniques. From the synchrotron FTIR measurements it can be proven that amide is present in the centre of the calcifications and the intensity of the bands depends on the pathology. Special attention is paid to the type of carbonate substitution in the calcifications relating to different pathology grades. In contrast to mammography, Raman spectroscopy has the capability to distinguish calcifications based on their chemical composition. The ultimate goal is to turn the acquired knowledge from the mapping studies into a clinical tool based on deep Raman spectroscopy. Deep Raman techniques have a considerable potential to reduce large numbers of normal biopsies, reduce the time delay between screening and diagnosis and therefore diminish patient anxiety. In order to achieve this, a deep Raman system is designed and after evaluation of its performance tested on buried calcification standards in porcine soft tissue and human mammary tissue. It is shown that, when the calcification is probed through tissue, the strong 960 cm-1 phosphate band can be used as a pseudo marker for carbonate substitution which is related to the pathology of the surrounding tissue. Furthermore, the first study in which human breast calcifications are measured in bulk tissue with a thickness of several millimetres to centimetres is presented. To date, measurements have been performed at 41 specimens with a thickness up to 25 mm. Measurements could be performed through skin and blue dye. The proposed deep Raman technique is promising for probing of calcifications through tissue but will need refinement before being adopted in hospitals.

The Maya of Central America developed a complex society: among their many achievements they developed a writing system, complex calendar and were prolific builders. The buildings of their large urban centres, such as Copan in Honduras, were decorated with painted stucco, moulded masks, carving and elaborate murals, using a range of coloured pigments. In this study the paints used on the buildings of Copan and some ceramic sherds have been investigated, non-destructively, using micro-Raman spectroscopy, micro-ATR infrared spectroscopy, environmental scanning electron microscopy with energy dispersive X-ray analysis (ESEM-EDX) and FTIR-ATR imaging spectroscopy. The paint samples come from four buildings and one tomb covering three time periods in the four hundred year history of Copan. The main pigment used in the red paint on these samples was identified as haematite, and the stucco as a mixture of calcite particles dispersed throughout a calcite-based lime wash stucco. The composition and physical nature of the stucco changed through time, indicating a refining of production techniques over this period. A range of minor mineral components have been identified in each of the samples including rutile, quartz, clay and carbon. The presence and proportion of these and other minerals differed in each sample, leading to unique mineral signatures for the paint from each time period. Green and grey paints have also been identified on one of the buildings, the Rosalila Temple. The green pigment was identified as a celadonite-based green earth, and the grey pigment as a mixture of carbon and muscovite. The combination of carbon and mica to create a reflective paint is a novel finding in Maya archaeology. The high spatial resolution of the micro-FTIR-ATR spectral imaging system has been used to resolve individual particles in tomb wall paint and to identify their mineralogy from their spectra. This system has been used in combination with micro-Raman spectroscopy and ESEM-EDX mapping to characterize the paint, which was found to be a mixture of haematite and silicate particles, with minor amounts of calcite, carbon and magnetite particles, in a sub-micron haematite and calcite matrix. The blending of a high percentage of silicate particles into the haematite pigment is unique the tomb sample. The stucco in this tomb wall paint has finely ground carbon dispersed throughout the top layer providing a dark base for the paint layer. Changing paint mixtures and stucco composition were found to correlate with changes in paint processing techniques and building construction methods over the four hundred years of site occupation.

El principal motor en el desarrollo e investigación de nuevos materiales biodegradables o ecológicos son las políticas medioambientales actuales junto con la concienciación por parte de los consumidores respecto a la utilización y consumo de materiales de bajo impacto ambiental o respetuosos con el medioambiente. Uno de los principales campos de generación de residuos es el del envasado de productos, y sobre todo, de alimentación. Las nuevas tendencias de consumismo de la sociedad actual generan gran cantidad de residuos que deben ser gestionados correctamente para generar el menor impacto ambiental posible. Es evidente que los plásticos forman una importante parte de este tipo de residuos, y que debido a su naturaleza petroquímica, son difíciles y caros de reciclar, sobre todo por la problemática de separación en origen. Por este motivo, los materiales poliméricos están ocupando importantes líneas de investigación debido al interés en sustituir materiales de origen petroquímico por materiales poliméricos de origen natural o biopolímeros. Por una parte, se afronta la problemática de la disminución de recursos procedentes de fuerzas fósiles; y por otra, la facilidad de eliminación de los residuos o biodegradabilidad. Uno de estos tipos de polímeros de gran demanda es el ácido poliláctico (PLA) con cada vez mayor número de aplicaciones en el sector industrial. Este tipo de aplicaciones requiere, en muchos casos, condiciones de adhesión o pegado según el diseño del producto. Debido a la intrínsecamente baja humectabilidad de este tipo de biopolímero, las uniones adhesivas presentan muy baja resistencia. Este problema justifica la búsqueda de tratamientos de modificación superficial que mejoren esta baja humectabilidad. Existen distintos tipos de tratamientos de modificación superficial, tanto físicos como químicos. Los tratamientos químicos, en general, al utilizar productos químicos que ataquen la superficie polimérica suelen originar residuos, que por su naturaleza son perjudiciales para el medioambiente. Por este motivo, los tratamientos que no generen residuos son más interesantes. Dentro de este ámbito, son óptimos los tratamientos basados en tecnología de plasma, ya que además de ser medioambientalmente correctos, sólo modifican la superficie a tratar sin cambiar las propiedades generales de comportamiento del propio material. El presente trabajo pretende mejorar la resistencia en adhesión de polímeros biodegradables de ácido poliláctico (PLA) con adhesivos de carácter natural, mediante la utilización del tratamiento de plasma atmosférico. La evaluación de los efectos de este tratamiento superficial sobre el PLA se realiza de forma experimental mediante la cuantificación de la variación de humectabilidad, después de tratar el sustrato de PLA a distintas velocidades y distancias toberasustrato. Las técnicas de estudio de los mecanismos de modificación superficial del plasma se han realizado para comprobar la efectividad del tratamiento de plasma atmosférico efectuando un análisis de espectroscopía fotoelectrónica de rayos X (XPS) y otro de espectroscopía infrarroja por transformada de Fourier con Reflectancia Total Atenuada (FTIR-ATR) observando la activación química de la superficie. Seguidamente se ha cuantificado la modificación física de la superficie del material mediante la técnica microscopía de fuerza atómica (AFM) y la microscopía electrónica de barrido (SEM). Los resultados experimentales permiten analizar una interesante mejora de la resistencia de las uniones adhesivas PLA/PLA. Además se determinan los rangos de trabajo óptimos para la utilización del plasma atmosférico, y así como la evaluación de la durabilidad de los efectos del plasma atmosférico sobre la superficie del PLA tratado. Los resultados obtenidos en el presente estudio demuestran que los mejores resultados alcanzados en el tratamiento superficial con plasma atmosférico han sido para condiciones de tratamiento de velocidades de pasada de la superficie de PLA bajo la tobera generadora del plasma lentas [100-300 mm/s]; y/o distancias toberasustrato bajas, alrededor de 10 mm. Como se ha podido comprobar en los resultados de XPS, la activación superficial es el mecanismo principal en la activación de la superficie del PLA, debido a la inserción de especies polares. Estas especies van variando a lo largo del tiempo de envejecimiento influyendo de forma negativa en la humectabilidad del sustrato. A parte de los cambios químicos, surgen cambios físicos por arranque de material que favorece en la mejora de las propiedades de adhesión del sustrato de PLA. El tratamiento de plasma atmosférico es un método apropiado para la mejora de las propiedades adhesivas de las superficies del PLA, así como muy interesante desde el punto de vista industrial, debido a la fácil implantación y flexibilidad en un proceso de producción en continuo y por tratase de una tecnología muy respetuosa con el medio ambiente. / Jordá Vilaplana, A. (2013). Optimización de las propiedades de uniones adhesivas de polímeros biodegradables de ácido poliláctico (PLA) con adhesivos de carácter natural mediante el empleo de tecnologías de plasma atmosférico [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/30061 / Alfresco

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Les glycoprotéines de fusion virales de classe 1 contrôlent la fusion entre lenveloppe virale et la membrane cellulaire. Ces glycoprotéines présentent une extrémité N-terminale indispensable à la fusion, le peptide de fusion. Les peptides de fusion sont capables dinduire à eux seuls la fusion de membranes in vitro. Dans cette étude, nous avons dabord analysé les peptides de fusion de gp41 du HIV et de gp30 du BLV. Ces deux peptides de fusion sont des peptides obliques : ils sinsèrent obliquement dans la membrane sous forme hélicoïdale. Nos études ont montré une relation entre la capacité de ces deux peptides de fusion à sinsérer obliquement dans la membrane et la capacité de leurs glycoprotéines de fusion à induire la fusion. Dans le cas du BLV, nous avons également montré une relation entre lobliquité du peptide de fusion et sa fusogénicité. Cette relation obliquité-fusogénicité a été utilisée pour prédire avec succès la région minimale des deux peptides de fusion suffisante pour induire une fusion significative in vitro, qui correspond respectivement aux douze et aux quinze premiers acides aminés de gp41 et gp30. Nos résultats montrent également que le peptide caméléon, un peptide de novo avec une structure labile, sinsère obliquement dans la membrane et induit la fusion in vitro. Le fait que ce peptide fasse partie des peptides obliques, comme les peptides de fusion du HIV et BLV, renforce lhypothèse dun lien entre la fusogénicité des peptides de fusion et leur flexibilité structurale. De nombreuses études réalisées sur les glycoprotéines de fusion de classe 1 indiquent que le domaine transmembranaire intervient également dans la fusion virale. Ce domaine doit être suffisamment long pour que la fusion soit complète. Dans ce travail, nous avons montré quun peptide transmembranaire modèle, le peptide KALR, est capable de sinsérer et dinduire la fusion de liposomes in vitro. En comparant les résultats de modélisation moléculaire avec ceux de FTIR et ceux de la fusion de phase lipidique/perméabilisation de liposomes, nous avons également montré que le taux dinsertion membranaire et la fusogénicité de KALR dépendent de la longueur de son cur hydrophobe. En effet, le taux dinsertion de KALR dans la membrane est beaucoup plus important lorsquil contient un cur hydrophobe lui permettant de traverser entièrement la membrane. Dans cette situation, KALR est capable dinduire la déstabilisation et la fusion de membranes alors que lorsque son cur hydrophobe est trop court pour lui permettre de traverser la membrane, il en est incapable. Ces résultats ont permis dapporter des éléments de compréhension des mécanismes intervenant lors de la fusion induite par les glycoprotéines de fusion virales. / Abstract: Class 1 fusion glycoproteins of viruses are involved in the fusion between viral envelope and cell membrane. The N-terminal extremity of these glycoproteins, called fusion peptide, is essential for fusion. Fusion peptides are able to induce by themselves in vitro membrane fusion. Firstly, we analysed fusion peptides of HIV-1 gp41 and BLV gp30. These two peptides are tilted peptides: they insert obliquely in the membrane when helical. Our studies showed a correlation between the ability of these two fusion peptides to insert obliquely in the membrane and the ability of whole glycoproteins to induce fusion. For BLV, a relationship between the obliquity of the fusion peptide and its fusogenicity was also observed. This obliquity/fusogenicity relationship was used to successfully predict the minimal region of the two fusion peptides sufficient to induce significant in vitro fusion. The minimal fusion peptide corresponds respectively to the twelve and to the fifteen first residues of gp41 and gp30. Our results also showed that the chameleon peptide, a de novo peptide with structural flexibility, inserts obliquely into the membrane and induces in vitro fusion. The fact that this peptide is a tilted peptide, like fusion peptides of HIV-1 and BLV, confirms the hypothesis of a relationship between the fusion peptides fusogenicity and their structural flexibility. A lot of studies on class 1 fusion glycoproteins of viruses indicate that the transmembrane domain is also directly involved in the viral fusion. Glycoproteins must have a domain long enough to induce complete fusion. In this study, we showed that a model transmembrane peptide, KALR peptide, is able to insert into membranes and to induce their fusion. By comparing molecular modelling results with those of FTIR, of liposomes lipid-mixing and of liposomes leakage, we also showed that the insertion rate into the membranes and the fusogenicity of KALR depend on the length of its hydrophobic core. Indeed, the insertion rate of KALR into the membrane is greatly larger when it contains a hydrophobic core long enough to allow the peptide to traverse the membrane. In this situation, KALR is able to destabilize membranes and to induce their fusion, while when it is too short to match the membrane, it is unable to induce fusion. These results allow to better understanding mechanisms involved in the fusion induced by viral fusion glycoproteins.