Luciane Ferreira Trierweiler

A New Approach for Practical Identifiability Analysis Applied to Dynamic Phenomenological Models

Abstract Identifiability analysis is an essential tool for parameter estimation of dynamic models. The objective of this technique is to verify which parameters of this model should be identified. This paper proposes a new methodology, based in control system theory applied to the local sensitivity analysis of the model. First, the sensitivity matrix is scaled by applying an optimization problem that minimizes the condition number of the system. Then, analyzing the NSRGA matrix of the system, the most appropriated subset of parameters to be estimated is selected. To assess the proposed methodology, a case study is presented.

Evaluation of wavelength selection methods for 2D fluorescence spectra applied to bioprocesses characterization

In biotechnological processes, the productivity and costs depend strongly on the control of the operating conditions. For this reason, sensors that allow the monitoring of variables of interest become quite important. 2D fluorescence spectroscopy is one promising option among those that are being applied for this purpose. In the present work, three methods were evaluated to select the best excitation/emission wavelength pairs of 2D fluorescence spectra to infer product, substrate and cellular concentrations throughout a fermentation using a multiple linear chemometric model: Exhaustive Search (ES), Stepwise Regression and Genetic Algorithm (GA). The Stepwise Regression presented unsatisfying results, while GA always led to good R2 values in short computational times. However, for the proposed problem, the ES showed the best performance, finding the global optimum in a few minutes.

Industrial Production of Polymeric Nanoparticles: Alternatives and Economic Analysis

A number of studies in the last 20 years describe the development of several techniques to produce a great variety of nanoparticles applied as drug delivery systems, among them, the nanoprecipitation. However, no study analyzing the profitability of such systems was found in the literature. Therefore, in this work it is analyzed the profitability of a polymeric nanoproduct produced by the method of nanoprecipitation: the bezophenone-3, a sunscreen agent. Based on the laboratory procedures, 3 alternatives were proposed for the industrial production, including a static mixer and a ceramic membrane pre-filtration step. The simplified profitability analysis was done based on a methodology called Bare Module Cost. Its results showed that lowest sale prices were achieved when the particles are produced through the most simplified process and dividing the production in more batches per day. The procedure presented in this chapter is general and can be widely applied to other type of nanoparticles and processes.

Estudo de um consórcio de microalgas na remoção de nutrientes de efluentes de curtume

A microalgas se multiplicam rapidamente em aguas ricas em nutrientes ou eutrofizadas, principalmente com altas cargas de fosforo e nitrogenio. Algumas pesquisas tem buscado por especies capazes de crescer em efluentes industriais explorando as vantagens das microalgas em remover os nutrientes dos efluentes e gerar biomassa com valores agregados. O presente trabalho teve como o objetivo testar um consorcio de microalga no tratamento de efluente de curtume. Foi acompanhado o crescimento das microalgas no efluente e a remocao de nutrientes associada a este processo. O consorcio se mostrou eficiente acarretando remocoes de Nitrogenio e Fosforo de 88,61% e 92,58%, respectivamente e foi possivel isolar uma cultura unialgal do microrganismo mais representativo.

Fluorescence Spectroscopy as a Tool for Ethanol Fermentation On-line Monitoring

Abstract In this work the technique of fluorescence spectroscopy was investigated as a tool to measure the main variables of interest in the production of ethanol from sugarcane juice. In order to do that, a methodology for the construction of chemometric models based on the intensities presented by excitation/emission pairs in the fluorescence spectra was proposed and tested. The results indicate that it is a promising technique, but still demanding further studies about the influence of broth composition in the spectra and how to take it into consideration in the chemometric modeling.