993 resultados para green processes
Resumo:
A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
Resumo:
A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
Resumo:
Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica
Resumo:
Dissertação para obtenção do Grau de Mestre em Engenharia e Gestão Industrial
Resumo:
Dissertação para obtenção do Grau de Mestre em Biotecnologia
Resumo:
RESUMO - Durante todo o seu ciclo de vida, o medicamento está sujeito a padrões de qualidade, segurança e eficácia, alicerçados numa atuação conjunta dos responsáveis pela sua colocação no mercado, das autoridades competentes nacionais e comunitárias. Os diferentes intervenientes estão sujeitos a um conjunto de obrigações e procedimentos que englobam também a sua fase final de retirada do mercado, devolução, recolha e valorização ou reciclagem. Neste trabalho é caracterizada a cadeia de distribuição do medicamento assim como o seu fluxo físico no sentido inverso, ou seja, o processo de devolução e de tratamento ambientalmente adequado para os resíduos de medicamentos. A maioria da literatura a respeito das devoluções de medicamentos enfatiza a vertente ecológica do sistema de logística inversa. Neste trabalho, as questões ambientais são discutidas , mas o objectivo primário focaliza questões económicas relacionadas com o processo de devoluções. São apresentadas as possíveis vantagens teóricas da criação de um sistema centralizado de gestão de devoluções, por oposição ao atual sistema de circuitos dispersos. Com a aplicação de um inquérito a armazenistas com larga responsabilidade no processo de devoluções, pretendeu-se avaliar os custos inerentes ao atual modelo. Os resultados obtidos indicam que existe margem potencial para reduzir custos neste processo, para a grande maioria dos armazenistas. Na área específica dos medicamentos fora de prazo de validade, o crescente desenvolvimento e aperfeiçoamento dos processos de devolução poderá direcionar-se no sentido da criação de centrais de devolução centralizadas.
Resumo:
Dissertation presented to obtain the Ph.D degree in Engineering and Technology Sciences, Biotechnology.
Resumo:
Dissertation presented to obtain the Ph.D degree in Engineering and Technology Sciences, Chemical Engineering.
Resumo:
Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica
Resumo:
Dissertation to obtain the degree of Master in Chemical and Biochemical Engineering
Staging the Scientist: The Representation of Science and its Processes in American and British Drama
Resumo:
Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Estudos Ingleses e Norte Americanos
Resumo:
Using a green methodology, 17 different poly(2-oxazolines) were synthesized starting from four different oxazoline monomers. The polymerization reactions were conducted in supercritical carbon dioxide under a cationic ring-opening polymerization (CROP) mechanism using boron trifluoride diethyl etherate as the catalyst. The obtained living polymers were then end-capped with different types of amines, in order to confer them antimicrobial activity. For comparison, four polyoxazolines were end-capped with water, and by their hydrolysis the linear poly(ethyleneimine) (LPEI) was also produced. After functionalization the obtained polymers were isolated, purified and characterized by standard techniques (FT-IR, NMR, MALDI-TOF and GPC). The synthesized poly(2-oxazolines) revealed an unusual intrinsic blue photoluminescence. High concentration of carbonyl groups in the polymer backbone is appointed as a key structural factor for the presence of fluorescence and enlarges polyoxazolines’ potential applications. Microbiological assays were also performed in order to evaluate their antimicrobial profile against gram-positive Staphylococcus aureus NCTC8325-4 and gram-negative Escherichia coli AB1157 strains, two well known and difficult to control pathogens. The minimum inhibitory concentrations (MIC)s and killing rates of three synthesized polymers against both strains were determined. The end-capping with N,N-dimethyldodecylamine of living poly(2- methyl-2-oxazoline) and poly(bisoxazoline) led to materials with higher MIC values but fast killing rates (less than 5 minutes to achieve 100% killing for both bacterial species) than LPEI, a polymer which had a lower MIC value, but took a longer time to kill both E.coli and S.aureus cells. LPEI achieved 100% killing after 45 minutes in contact with E. coli and after 4 hours in contact with S.aureus. Such huge differences in the biocidal behavior of the different polymers can possibly underlie different mechanisms of action. In the future, studies to elucidate the obtained data will be performed to better understand the killing mechanisms of the polymers through the use of microbial cell biology techniques.
Resumo:
Software development is a discipline that is almost as old as the history of computers. With the advent of the Internet and all of its related technologies, software development has been on high demand. But, and especially in SME (small and medium enterprise), this was not accompanied with a comparable effort to develop a set of sustainable and standardized activities of project management, which lead to increasing inefficiencies and costs. Given the actual economic situation, it makes sense to engage in an effort to reduce said inefficiencies and rising costs. For that end, this work will analyze the current state of software development’s project management processes on a Portuguese SME, along with its problems and inefficiencies in an effort to create a standardized model to manage software development, with special attention given to critical success factors in an agile software development environment, while using the best practices in process modeling. This work also aims to create guidelines to correctly integrate these changes in the existing IS structure of a company.
Resumo:
The use of natural pigments instead of synthetic colourants is receiving growing interest in the food industry. In this field, cactus pears (Opuntia spp.) have been identified to be a promising betalainic crops covering a wide coloured spectrum. The aim of this work was to develop adequate clean and mild methodologies for the isolation and encapsulation of betacyanins, from cactus pear fruits (Opuntia spp.). Firstly, two different emerging technologies, namely PLE (Pressurized Liquid Extraction) and HPCDAE (High Pressure Carbon Dioxide-Assisted Extraction), were exploited to isolation of betacyanins form cactus pear fruits. Different process conditions were tested for the maximum recovery of betacyanins. Results showed that highest extraction yields were achieved for HPCDAE and mass ratio of pressurized carbon dioxide vs. acidified water was the parameter that most affected the betacyanins extraction. At optimum conditions of HPCDAE, Opuntia spp. extract presented a total betacyanin content of 211 ± 10 mg/100 g whereas extracts obtained using conventional extraction, PLE in static and in dynamic mode presented a total betacyanin content of 85 ± 3, 191 ± 2 and 153 ± 5 mg/100 g, respectively. HPCDAE has proven to be a successful technology to extract betacyanins from Opuntia spp. fruits. Afterward, Supercritical Fluid Technology was exploited to develop lipidic particles of betalain-rich extract. A betacyanin-rich conventional extract was encapsulated by PGSS® (Particles from Gas Saturated Solutions) technique. Different process conditions were tested in order to model the encapsulation of betacyanins. The pressure had a negative effect on betacyanin encapsulation. Lower pressures leads to an increase in the betacyanin encapsulation. This effect was more pronounced at higher temperatures and lower equilibrium time. At these conditions, Opuntia spp. particles presented 64.4 ± 4.5 mg/100 g and high antioxidant capacity. When compared with the Opuntia spp. dried extract, lipidic particles contributed to a better homogenization of the pink colour after incorporation in ice cream.
Resumo:
Spin-lattice Relaxation, self-Diffusion coefficients and Residual Dipolar Couplings (RDC’s) are the basis of well established Nuclear Magnetic Resonance techniques for the physicochemical study of small molecules (typically organic compounds and natural products with MW < 1000 Da), as they proved to be a powerful and complementary source of information about structural dynamic processes in solution. The work developed in this thesis consists in the application of the earlier-mentioned NMR techniques to explore, analyze and systematize patterns of the molecular dynamic behavior of selected small molecules in particular experimental conditions. Two systems were chosen to investigate molecular dynamic behavior by these techniques: the dynamics of ion-pair formation and ion interaction in ionic liquids (IL) and the dynamics of molecular reorientation when molecules are placed in oriented phases (alignment media). The application of NMR spin-lattice relaxation and self-diffusion measurements was applied to study the rotational and translational molecular dynamics of the IL: 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4]. The study of the cation-anion dynamics in neat and IL-water mixtures was systematically investigated by a combination of multinuclear NMR relaxation techniques with diffusion data (using by H1, C13 and F19 NMR spectroscopy). Spin-lattice relaxation time (T1), self-diffusion coefficients and nuclear Overhauser effect experiments were combined to determine the conditions that favor the formation of long lived [BMIM][BF4] ion-pairs in water. For this purpose and using the self-diffusion coefficients of cation and anion as a probe, different IL-water compositions were screened (from neat IL to infinite dilution) to find the conditions where both cation and anion present equal diffusion coefficients (8% water fraction at 25 ºC). This condition as well as the neat IL and the infinite dilution were then further studied by 13C NMR relaxation in order to determine correlation times (c) for the molecular reorientational motion using a mathematical iterative procedure and experimental data obtained in a temperature range between 273 and 353 K. The behavior of self-diffusion and relaxation data obtained in our experiments point at the combining parameters of molar fraction 8 % and temperature 298 K as the most favorable condition for the formation of long lived ion-pairs. When molecules are subjected to soft anisotropic motion by being placed in some special media, Residual Dipolar Couplings (RDCs), can be measured, because of the partial alignment induced by this media. RDCs are emerging as a powerful routine tool employed in conformational analysis, as it complements and even outperforms the approaches based on the classical NMR NOE or J3 couplings. In this work, three different alignment media have been characterized and evaluated in terms of integrity using 2H and 1H 1D-NMR spectroscopy, namely the stretched and compressed gel PMMA, and the lyotropic liquid crystals CpCl/n-hexanol/brine and cromolyn/water. The influence that different media and degrees of alignment have on the dynamic properties of several molecules was explored. Different sized sugars were used and their self-diffusion was determined as well as conformation features using RDCs. The results obtained indicate that no influence is felt by the small molecules diffusion and conformational features studied within the alignment degree range studied, which was the 3, 5 and 6 % CpCl/n-hexanol/brine for diffusion, and 5 and 7.5 % CpCl/n-hexanol/brine for conformation. It was also possible to determine that the small molecules diffusion verified in the alignment media presented close values to the ones observed in water, reinforcing the idea of no conditioning of molecular properties in such media.