54,545 research outputs found

    Desarrollo de papeles biocativos por injerto de moléculas específicas en celulosa

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    Tesis (DCI)--FCEFN-UNC, 2019En la presente tesis se presenta el desarrollo de papeles bioactivos con potencial aplicaci√≥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 √°cido policarbox√≠lico como agente ligante. Con el objetivo de evaluar la escalabilidad del proceso propuesto, se estudiaron distintas tecnolog√≠as de curado, tales como calentamiento por convecci√≥n, infrarrojo, microondas y conducci√≥n. En todos los casos, se analizaron la influencia de las variables operativas sobre el avance de la reacci√≥n y propiedades finales del papel preparado, utilizando un dise√Īo de experimentos Doehlert para elegir las experiencias a realizar, y analizando los resultados mediante metodolog√≠a de superficie de respuesta y an√°lisis estad√≠stico ANOVA. Se pudo comprobar que la reacci√≥n de injerto de eugenol en papel comercial se produjo con √©xito en todas las tecnolog√≠as estudiadas. Asimismo, se encontraron las condiciones √≥ptimas de reacci√≥n para cada una de las tecnolog√≠as, para lo cual se busc√≥ un compromiso entre el avance de la reacci√≥n y las propiedades finales del material (mec√°nicas y color). A partir de estas condiciones, se prepararon papeles y se realiz√≥ una caracterizaci√≥n m√°s espec√≠fica para su aplicaci√≥n como envase de alimentos comparando los papeles modificados con el papel virgen. Se analizaron las propiedades mec√°nicas por ensayo de tracci√≥n, rasgado y punzonado y se midi√≥ la absorci√≥n de agua y la capacidad de degradaci√≥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√≠sticas f√≠sicas y bioactivas para su posible aplicaci√≥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√≥ la migraci√≥n de reactivos, propiedades organol√©pticas y conservaci√≥n del alimento, arrojando resultados promisorios para la industria de envases de alimentos. Finalmente, se realiz√≥ una comparaci√≥n de las tecnolog√≠as de curado ensayadas, analizando diferentes aspectos como avance de reacci√≥n, propiedades finales, apariencia, tiempo de reacci√≥n, consumo de energ√≠a, entre otros, como as√≠ tambi√©n disponibilidad y uso de estas tecnolog√≠as a escala industrial, seleccionando la tecnolog√≠a de conducci√≥n como la m√°s adecuada para una propuesta de escalado industrial.Fil: Muratore, Florencia. Universidad Nacional de C√≥rdoba. Facultad de Ciencias Exactas, F√≠sicas y Naturales; Argentina.Fil: Muratore, Florencia. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Instituto de Investigaci√≥n y Desarrollo en Ingenier√≠a de Procesos y Qu√≠mica Aplicada; Argentina

    Analysis of reliable deployment of TDOA local positioning architectures

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    .Local Positioning Systems (LPS) are supposing an attractive research topic over the last few years. LPS are ad-hoc deployments of wireless sensor networks for particularly adapt to the environment characteristics in harsh environments. Among LPS, those based on temporal measurements stand out for their trade-off among accuracy, robustness and costs. But, regardless the LPS architecture considered, an optimization of the sensor distribution is required for achieving competitive results. Recent studies have shown that under optimized node distributions, time-based LPS cumulate the bigger error bounds due to synchronization errors. Consequently, asynchronous architectures such as Asynchronous Time Difference of Arrival (A-TDOA) have been recently proposed. However, the A-TDOA architecture supposes the concentration of the time measurement in a single clock of a coordinator sensor making this architecture less versatile. In this paper, we present an optimization methodology for overcoming the drawbacks of the A-TDOA architecture in nominal and failure conditions with regards to the synchronous TDOA. Results show that this optimization strategy allows the reduction of the uncertainties in the target location by 79% and 89.5% and the enhancement of the convergence properties by 86% and 33% of the A-TDOA architecture with regards to the TDOA synchronous architecture in two different application scenarios. In addition, maximum convergence points are more easily found in the A-TDOA in both configurations concluding the benefits of this architecture in LPS high-demanded applicationS

    Interactive Sonic Environments: Sonic artwork via gameplay experience

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    The purpose of this study is to investigate the use of video-game technology in the design and implementation of interactive sonic centric artworks, the purpose of which is to create and contribute to the discourse and understanding of its effectiveness in electro-acoustic composition highlighting the creative process. Key research questions include: How can the language of electro-acoustic music be placed in a new framework derived from videogame aesthetics and technology? What new creative processes need to be considered when using this medium? Moreover, what aspects of 'play' should be considered when designing the systems? The findings of this study assert that composers and sonic art practitioners need little or no coding knowledge to create exciting applications and the myriad of options available to the composer when using video-game technology is limited only by imagination. Through a cyclic process of planning, building, testing and playing these applications the project revealed advantages and unique sonic opportunities in comparison to other sonic art installations. A portfolio of selected original compositions, both fixed and open are presented by the author to complement this study. The commentary serves to place the work in context with other practitioners in the field and to provide compositional approaches that have been taken

    South Yorkshire low carbon energy supply chains: hydrogen sector summary

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    The company she keeps : The social and interpersonal construction of girls same sex friendships

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    This thesis begins a critical analysis of girls' 'private' interpersonal and social relations as they are enacted within two school settings. It is the study of these marginal subordinated worlds productivity of forms of femininity which provides the main narrative of this project. I seek to understand these processes of (best) friendship construction through a feminist multi-disciplinary frame, drawing upon cultural studies, psychoanalysis and accounts of gender politics. I argue that the investments girls bring to their homosocial alliances and boundary drawing narry a psychological compulsion which is complexly connected to their own experiences within the mother/daughter bond as well as reflecting positively an immense social debt to the permissions girls have to be nurturant and ; negatively their own reproduction of oppressive exclusionary practices. Best friendship in particular gives girls therefore, the experience of 'monogamy' continuous of maternal/daughter identification, reminiscent of their positioning inside monopolistic forms of heterosexuality. But these subcultures also represent a subversive discontinuity to the public dominance of boys/teachers/adults in schools and to the ideologies and practices of heterosociality and heterosexuality. By taking seriously their transmission of the values of friendship in their chosen form of notes and diaries for example, I was able to access the means whereby they were able to resist their surveillance and control by those in power over them. I conclude by arguing that it is through a recognition of the valency of these indivisiblly positive and negative aspects to girls cultures that Equal Opportunities practitioners must begin if they are serious about their ambitions. Methods have to be made which enable girls to transfer their 'private' solidarities into the 'public' realm, which unquestionably demands contesting with them the causes and consequences of their implication in the divisions which also contaminate their lives and weaken them

    Studies of strategic performance management for classical organizations theory & practice

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    Nowadays, the activities of "Performance Management" have spread very broadly in actually every part of business and management. There are numerous practitioners and researchers from very different disciplines, who are involved in exploring the different contents of performance management. In this thesis, some relevant historic developments in performance management are first reviewed. This includes various theories and frameworks of performance management. Then several management science techniques are developed for assessing performance management, including new methods in Data Envelopment Analysis (DEA) and Soft System Methodology (SSM). A theoretical framework for performance management and its practical procedures (five phases) are developed for "classic" organizations using soft system thinking, and the relationship with the existing theories are explored. Eventually these results are applied in three case studies to verify our theoretical development. One of the main contributions of this work is to point out, and to systematically explore the basic idea that the effective forms and structures of performance management for an organization are likely to depend greatly on the organizational configuration, in order to coordinate well with other management activities in the organization, which has seemingly been neglected in the existing literature of performance management research in the sense that there exists little known research that associated particular forms of performance management with the explicit assumptions of organizational configuration. By applying SSM, this thesis logically derives some main functional blocks of performance management in 'classic' organizations and clarifies the relationships between performance management and other management activities. Furthermore, it develops some new tools and procedures, which can hierarchically decompose organizational strategies and produce a practical model of specific implementation steps for "classic" organizations. Our approach integrates popular types of performance management models. Last but not least, this thesis presents findings from three major cases, which are quite different organizations in terms of management styles, ownership, and operating environment, to illustrate the fliexbility of the developed theoretical framework

    Drivers and barriers to Sustainability practices in the Zambian Construction Industry

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    Zambia, and Sub-Sahara Africa (SSA) generally, is lagging behind in the area of sustainable construction due to several barriers to the implementation of sustainable construction. This study therefore explored drivers and barriers to the adoption of sustainable construction practices in Zambia. The study could inform stakeholders on measures which could improve the implementation of sustainable construction. The study used an online quantitative questionnaire survey of construction professionals and clients. A total of 112 responses were received representing various stakeholder groups in the construction industry. The data were subjected to factor analysis and ranked using the relative importance index. The data show that drivers to sustainable construction cluster into three constructs namely, environment and health-related factors, regulatory and industry-related factors and, economy and firm related factors. Barriers clustered into three groups namely, awareness and knowledge related factors, regulatory and industry-related factors and, economy and cost-related factors. Therefore, measures aimed at improving sustainable construction in Zambia should focus attention on these broad clusters
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