43,525 research outputs found

    Desarrollo de papeles biocativos por injerto de mol茅culas espec铆ficas en celulosa

    Get PDF
    Tesis (DCI)--FCEFN-UNC, 2019En la presente tesis se presenta el desarrollo de papeles bioactivos con potencial aplicaci贸n en el envasado activo de alimentos. Para tal fin, se propuso el injerto de eugenol, un compuesto de origen natural con propiedades antimicrobiana, antioxidante y repelente de insectos, en celulosa, utilizando 谩cido policarbox铆lico como agente ligante. Con el objetivo de evaluar la escalabilidad del proceso propuesto, se estudiaron distintas tecnolog铆as de curado, tales como calentamiento por convecci贸n, infrarrojo, microondas y conducci贸n. En todos los casos, se analizaron la influencia de las variables operativas sobre el avance de la reacci贸n y propiedades finales del papel preparado, utilizando un dise帽o de experimentos Doehlert para elegir las experiencias a realizar, y analizando los resultados mediante metodolog铆a de superficie de respuesta y an谩lisis estad铆stico ANOVA. Se pudo comprobar que la reacci贸n de injerto de eugenol en papel comercial se produjo con 茅xito en todas las tecnolog铆as estudiadas. Asimismo, se encontraron las condiciones 贸ptimas de reacci贸n para cada una de las tecnolog铆as, para lo cual se busc贸 un compromiso entre el avance de la reacci贸n y las propiedades finales del material (mec谩nicas y color). A partir de estas condiciones, se prepararon papeles y se realiz贸 una caracterizaci贸n m谩s espec铆fica para su aplicaci贸n como envase de alimentos comparando los papeles modificados con el papel virgen. Se analizaron las propiedades mec谩nicas por ensayo de tracci贸n, rasgado y punzonado y se midi贸 la absorci贸n de agua y la capacidad de degradaci贸n. Por otro lado, las propiedades bioactivas analizadas fueron la actividad antioxidante, antimicrobiana, repelente e insecticida de gorgojos (T. castaneum y R. dominica). Una vez probado que el papel modificado presenta buenas caracter铆sticas f铆sicas y bioactivas para su posible aplicaci贸n en el envasado de alimentos, se realizaron prototipos de envasado para harina, como alimento representativo de alimentos derivados de cereales, susceptibles al ataque de plagas. En este estudio se analiz贸 la migraci贸n de reactivos, propiedades organol茅pticas y conservaci贸n del alimento, arrojando resultados promisorios para la industria de envases de alimentos. Finalmente, se realiz贸 una comparaci贸n de las tecnolog铆as de curado ensayadas, analizando diferentes aspectos como avance de reacci贸n, propiedades finales, apariencia, tiempo de reacci贸n, consumo de energ铆a, entre otros, como as铆 tambi茅n disponibilidad y uso de estas tecnolog铆as a escala industrial, seleccionando la tecnolog铆a de conducci贸n como la m谩s adecuada para una propuesta de escalado industrial.Fil: Muratore, Florencia. Universidad Nacional de C贸rdoba. Facultad de Ciencias Exactas, F铆sicas y Naturales; Argentina.Fil: Muratore, Florencia. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Instituto de Investigaci贸n y Desarrollo en Ingenier铆a de Procesos y Qu铆mica Aplicada; Argentina

    Desarrollo de materiales bioactivos con potencial aplicaci贸n odontol贸gica mediante impregnaci贸n asistida por CO2 supercr铆tico

    Get PDF
    Tesis (DCI)--FCEFN-UNC, 2021En esta tesis se estudi贸 el proceso de incorporaci贸n de eugenol en fibras de poliamida 6 (PA6) mediante la impregnaci贸n asistida por CO2 supercr铆tico para desarrollar un material con propiedades antimicrobianas con una potencial aplicaci贸n odontol贸gica. Para este prop贸sito, se construy贸 un equipo de alta presi贸n en el que se llevaron a cabo m煤ltiples ensayos de impregnaci贸n de eugenol y de sorci贸n de CO2 en un hilo dental comercial de PA6 en distintas condiciones de presi贸n y temperatura (40 鈥 60 掳C y 8 鈥 12 MPa). Con el fin de encontrar las mejores condiciones del proceso de impregnaci贸n, se evalu贸 la influencia de diferentes variables operativas (presi贸n, temperatura, tiempo de contacto y velocidad de despresurizaci贸n) sobre la cantidad de eugenol impregnada en el material. Adem谩s, se estudiaron los principales fen贸menos difusivos que ocurren en el proceso de impregnaci贸n del eugenol en condiciones supercr铆ticas. Para ello, se hicieron ensayos de cin茅tica de sorci贸n del CO2 y del eugenol en PA6 a diferentes condiciones de presi贸n y temperatura y se determin贸 el coeficiente de difusi贸n aparente para ambas especies en este pol铆mero. Por otra parte, se evaluaron las propiedades finales del material impregnado, analizando las propiedades mec谩nicas, t茅rmicas y morfol贸gicas del material original, presurizado con CO2 e impregnado con eugenol. Adicionalmente se evalu贸 la actividad antimicrobiana del material impregnado frente a dos bacterias comunes (Escherichia coli y Staphylococcus aureus). Asimismo, se estudi贸 la migraci贸n del compuesto activo impregnado en aire y en saliva artificial, obteniendo datos importantes para el potencial desarrollo de un producto comercial, como la estimaci贸n de la vida 煤til, el tipo de envase, y tipo de aplicaci贸n del producto. Finalmente, se hizo un dise帽o y dimensionamiento de un proceso industrial para la impregnaci贸n de eugenol en bobinas de fibras de PA6 en CO2 supercr铆tico, a partir de los datos de eficiencia de impregnaci贸n y par谩metros difusivos del hilo impregnado con eugenol previamente obtenidos, realizando el dise帽o de la bobina, el equipo impregnador y los c谩lculos de sus principales requerimientos de masa y energ铆a.Fil: Mosquera Ruiz, Jos茅 Euliser. Universidad Nacional de C贸rdoba. Facultad de Ciencias Exactas, F铆sicas y Naturales; Argentina.Fil: Mosquera Ruiz, Jos茅 Euliser. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Instituto de Investigaci贸n y Desarrollo en Ingenier铆a de Procesos y Qu铆mica Aplicada; Argentina

    Sexual violence as a form of social control : the role of hostile and benevolent sexism

    Get PDF
    This thesis examines the feminist hypothesis that rape functions as a tool of social control through which women are kept in subordinate social positions (Brownmiller, 1975). In examining this hypothesis, the current thesis explores the role of benevolent and hostile sexism in accounting for people's responses to different types of rape (i.e. stranger vs. acquaintance rape). An examination of the literature suggests that there are general societal beliefs in the distinction between "good" and "bad" rape victims (Pollard, 1992). Interestingly, researchers have observed that benevolent sexism (BS) is related to the idealisation of women in traditional gender roles (i.e. "good" women; Glick et aI., 2000). It is, therefore, argued that individuals who idealise women in traditional roles (i.e. high BS individuals) are more likely to negatively evaluate rape victims who can be perceived as violating these norms. Nine empirical studies are presented in this thesis. Study 1 examines the potential role of BS in accounting for previously observed differences in the amount of blame attributed to stranger and acquaintance rape victims (e.g. Pollard, 1992). Studies 2 and 3 examine the psychological mechanisms that underlie the relationship between BS and victim blame in acquaintance rape situations. Studies 2 and 4 also explore the psychological mechanisms that underlie the relationship between hostile sexism (HS) and self reported rape proclivity in acquaintance rape situations (c.f. Viki, 2000). In Study 5, the relationship between BS and paternalistic chivalry (attitudes that are simultaneously courteous and restrictive to women) is examined. Studies 6 and 7 examine the role of BS in accounting for participants' responses to stranger vs. acquaintance rape perpetrators. The last two studies (Studies 8 and 9) examine the potential role of legal verdicts in moderating the relationship between BS and victim blame in acquaintance rape cases. Taken together, the results support the argument that BS provides a psychological mechanism through which differences in the amount of blame attributed to stranger and acquaintance rape victims can be explained. In contrast, HS provides a mechanism for explaining differences in self-reported proclivity to commit stranger and acquaintance rape. The thesis concludes with a summary of the findings, a discussion of the methodological limitations of the studies and suggestions of directions for future research

    The interpretation of Islam and nationalism by the elite through the English language media in Pakistan.

    Get PDF
    The media is constructed and interpreted through what people 'know'. That knowledge is, forthe most part, created through day to day experiences. In Pakistan, Islam and nationalism aretwo components of this social knowledge which are intrinsically tied to the experiences of thePakistani people. Censorship and selection are means through which this knowledge isarticulated and interpreted.General conceptions of partially shared large scale bodies of knowledge and ideas reinforce,and are reinforced by, general medium of mass communication: the print and electronic media.Focusing on the govermnent, media institutions and Pakistani elites, I describe and analyse thedifferent, sometimes conflicting, interpretations of Islam and Pakistani nationalism manifest inand through media productions presented in Pakistan.The media means many things, not least of which is power. It is the media as a source ofpower that is so frequently controlled, directed and manipulated. The terminology may beslightly different according to the context within which one is talking - propaganda, selection,etc. - but ultimately it comes down to the same thing - censorship. Each of the three groups:government, media institutions and Pakistani elites - have the power to interpret and censormedia content and consideration must be taken of each of the other power holders consequentlyrestricting the power of each group in relation to the other two. The processes of thismanipulation and their consequences form the major themes of this thesis

    Political Islam and grassroots activism in Turkey : a study of the pro-Islamist Virtue Party's grassroots activists and their affects on the electoral outcomes

    Get PDF
    This thesis presents an analysis of the spectacular rise of political Islam in Turkey. It has two aims: first to understand the underlying causes of the rise of the Welfare Party which -later became the Virtue Party- throughout the 1990s, and second to analyse how grassroots activism influenced this process. The thesis reviews the previous literature on the Islamic fundamentalist movements, political parties, political party systems and concentrates on the local party organisations and their effects on the party's electoral performance. It questions the categorisation of Islamic fundamentalism as an appropriate label for this movement. An exploration of such movements is particularly important in light of the event of 11`x' September. After exploring existing theoretical and case studies into political Islam and party activism, I present my qualitative case study. I have used ethnographic methodology and done participatory observations among grassroots activists in Ankara's two sub-districts covering 105 neighbourhoods. I examined the Turkish party system and the reasons for its collapse. It was observed that as a result of party fragmentation, electoral volatility and organisational decline and decline in the party identification among the citizens the Turkish party system has declined. However, the WP/VP profited from this trend enormously and emerged as the main beneficiary of this process. Empirical data is analysed in four chapters, dealing with the different aspects of the Virtue Party's local organisations and grassroots activists. They deal with change and continuity in the party, the patterns of participation, the routes and motives for becoming a party activist, the profile of party activists and the local party organisations. I explore what they do and how they do it. The analysis reveals that the categorisation of Islamic fundamentalism is misplaced and the rise of political Islam in Turkey cannot be explained as religious revivalism or the rise of Islamic fundamentalism. It is a political force that drives its strength from the urban poor which has been harshly affected by the IMF directed neoliberal economy policies. In conclusion, it is shown that the WP/VP's electoral chances were significantly improved by its very efficient and effective party organisations and highly committed grassroots activists
    corecore