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Modelo matemático do processo de purificação do ácido clavulânico por troca iônica em coluna de leito fixo
(Universidade Federal de São Carlos, 2009-08-04) Cuel, Maressa Fabiano; Kwong, Wu Hong; https://lattes.cnpq.br/5750513580197013
Clavulanic acid (CA) is a β-lactam antibiotic produced industrially by submerged cultures of the filamentous bacterium Streptomyces clavuligerus. Due to its importance, several studies on the purification of clavulanic acid have been conducted at the Department of Chemical Engineering of the Federal University of São Carlos DEQ-UFSCar. As a natural sequence of these works, a need has been identified for greater knowledge about the CA adsorption process by mathematically modeling the incorporation of the phenomenon of CA degradation in the sites of resin through a first order reaction. Because amino acids stand out among the principal molecules that are found in fermented broth, it has become imperative for the development of the process to evaluate purification in terms of the amino acids present during the purification process. Some of these amino acids, e.g., tyrosines, present physicochemical properties similar to those of clavulanic acid. The process of batch absorption can be simulated by a mathematical model, providing kinetic and transport parameters involved in absorption. A mathematical model of the clavulanic acid purification process in a fixed-bed absorption column was developed to determine the rupture curve. The modeling allowed for the determination of several important process parameters, such as transport parameters and the intrinsic kinetic constants of absorption. A sensitivity analysis demonstrated that the mass transfer coefficient strongly influences the results of the model. The simulation of the process led to the conclusion that the process is limited both by the degradation stage during absorption and by the mass transfer, indicating that both factors must be taken into account in the analysis of this type of process in a fixed-bed column. It was also found that the degradation of CA in the resin sites is a factor that does not allow the rupture curve to reach the value of C/Co equal to 1, which explains the low yield of the CA process during absorption. This work also aimed to apply the sequencing method to solve the partial differential equations that represent the mathematical model which describes the adsorption of CA in Amberlite IRA-400 resin and to compare it with the finite difference method which is more commonly employed. The application of the proposed methodology in the clavulanic acid purification process in a packed column showed a good performance, with a rupture curve very similar to that obtained by the finite difference method, thus demonstrating the efficiency of the proposed method.
Situação atual e perspectivas de utilização de materiais no interior de aeronaves executivas
(Universidade Federal de São Carlos, 2009-08-04) Costa, Fábio Rodrigues; Gregolin, José Angelo Rodrigues; https://lattes.cnpq.br/7842651773105125; https://lattes.cnpq.br/9160734660960766
This study focuses on analyzing the current situation and perspectives of materials selection and utilization, like composites, decorative laminates and films, and others, in business aircraft, particularly in furnishings and its finishes, of great importance in this sector and systematically few studied. It was used technological prospective and competitive intelligence techniques like interviews with specialists, search in data and patents bases, analysis of existing studies and other sources. A case study was done on finishing materials, which are critical in the business aircraft class. Technological drivers for this sector, like air pollution reduction, personalization and simplicity of utilization, beyond others, were pointed out. It was verified that the materials selection is affected by several factors, namely: market segment involved, flight time and purpose and customer cultural differences, specially in relation to aesthetic, sensitive and comfort requirements; obligation to meet safety requirements from airworthiness agencies, specially in relation to inflammability and structural resistance and cabin safety; need of meeting design requirements, like low weight, high resistance/weight relation, fatigue resistance, degradation resistance, etc. In terms of patenting of cabin, interior and furnishings related technologies, Boeing, Airbus and Bombardier have been in highlighted position, while other business aircraft or interior manufacturers have appeared as owners of a relatively small number of patents. Important companies in key finishes (and their technologies) were identified by patents ownership. It was recommended that the materials selection and procurement process emphasizes the development and capability improvement of potential national suppliers, aiming at meeting business aviation requirements, as well as partnership with the relevant companies in patents ownership. A materials selection methodology was proposed, considering the researched context, which allows the maximization of aggregated value to the customer.
Estrutura genética das populações de abelhas africanizadas (Apis mellifera L.) e suas relações com as raças parentais determinadas por meio da análise de microssatélites
(Universidade Federal de São Carlos, 2009-08-04) Collet, Thaís; Del Lama, Marco Antonio; https://lattes.cnpq.br/7198095288825585; https://lattes.cnpq.br/3345994967493962
The Africanization process through the Americas started in 1956 with the introduction in Rio Claro (SP) of Apis mellifera scutellata queens from South Africa. The resultant alterations of this process in the characteristics of the preexisting honeybee populations have been measured through several methods, including morphometry, allozymes, mitochondrial DNA patterns and in a lower degree the microsatellite loci. The aim of this study was to determine the genetic structure of the A. mellifera Africanized populations from seven countries of South and Central Americas, employing 12 microsatellite loci. Parental populations from Europe and Africa were used as control. The results obtained from 2034 colonies analyzed indicated that the American Africanized populations presented a high variability and have essentially an African genetic constitution. The South region of Argentina is an exception since those samples keep the variation patterns of the European populations, with a lower degree of polymorphism. However, the presence of Africanized honeybees in high altitudes and low temperatures observed in Colombia indicate that the restrictions for the colonization of temperate regions by the Africanized swarms are not only due to the temperature. Concerning to the low frequencies of the European patterns in the Africanized populations, the contribution of genes characteristics of subspecies from the M lineage (A. m. iberiensis) is higher, with a very low proportion of C lineage genes (A. m. ligustica). Results of population structure indicate that the Africanized populations are genetically low differentiated. Even though a low fraction of European genes exists in the Africanized populations, we can affirm that the genetic constitution of the honeybees of Americas is a straight result of the introduction of A. m. scutellata in Brazil.