Percorrer por autor "Ferreira, Olga"
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- 14th International Chemical and Biological Engineering Conference (CHEMPOR-2023): Book of AbstractsPublication . Queiroz, Ana; Peres, António M.; Ribeiro, António E.; Barreiro, Filomena; Ferreira, Olga; Brito, Paulo; Pinho, SimãoWelcome to the 14th edition of the International Chemical and Biological Engineering Conference (ChemPor-2023) held at Bragança Polytechnic University (Instituto Politécnico de Bragança, IPB), Portugal, from 12 to 15 of September, 2023. This triennial conference, organized by a Portuguese Higher Education Institution and the Portuguese Engineers Association (Ordem dos Engenheiros), gathers experts from the chemical and biological engineering areas and related subjects to exchange knowledge and technological experiences within the academic, industrial, scientific, and technological communities. ChemPor-2023 addresses these research fields in different topics, from green chemistry to engineering education, always envisaging a sustainable development. The etymology of the word “conference”, from the Medieval Latin, means literally “bring together”. This 14th edition comes with a two-year delay following the global sanitary crisis since only a full inperson meeting could fulfill this purpose. ChemPor-2023 encompasses a gathering in a vivid, enlightening, and convivial way, and this hiatus did not limit this spirit or its objectives. The conference aims to celebrate creativity, diversity, and friendship among participants, promoting ideas exchange and fruitful interactions. We have circa 300 delegates from 4 continents, and your active participation is highly acknowledged. The general relevance of ChemPor-2023 is addressed in a variety of settings, including biorefinery, biotechnology, energy and environment, innovative materials, creation and design of novel reaction and separation processes, always foreseeing industrial applications for a sustainable shaping of the future. This edition includes an opening lecture by Jorge Calado in the immense but much less explored area of ArtScience, and an Honor Session dedicated to Alírio Rodrigues for his academic and scientific contributions, particularly regarding IPB. Besides, the conference includes 11 invited lectures from internationally recognized scientists and experts from the industry, 107 oral presentations distributed in 27 sessions, and 135 posters in two dedicated sessions. A session exclusively dedicated to companies and another for Ph.D. studies in industrial environments are to be highlighted. The “Professor Almiro e Castro” award, established in 2014 by PARALAB – Equipamentos Industrial and Laboratory SA, to recognize the scientific merit of a Portuguese professor or researcher in the last three years in the fields of Chemical and Biological Engineering, and related areas, will be announced at the closing of the conference. In that ceremony, the two best posters and the best oral communication awards by young scientists will also be granted. We want to reinforce our deepest appreciation to all the participants, but also to the members of the Honor, Scientific, and Local Organizing Committees for their invaluable contribution to the conference and acknowledge the institutional support of Instituto Politécnico de Bragança, Ordem dos Engenheiros, Centro de Investigação de Montanha, Sociedade Portuguesa de Química, and Câmara Municipal de Bragança. Expressing enormous gratitude is mandatory to all our Sponsors and associated scientific journals and publishers. Nothing could have been possible without all of you! Finally, our best wishes for success for the next ChemPor organization.
- A-UNIFAC modelling of binary and multicomponent phase equilibria of fatty esters+water+methanol+glycerolPublication . Garrido, Nuno M.; Ferreira, Olga; Lugo, Rafael; Hemptinne, Jean-Charles de; Macedo, Eugénia A.; Bottini, Susana B.The production of methyl and ethyl esters of fatty acids is of great industrial interest, considering the direct application of these esters as biodiesel. For biodiesel purification and by-products recovery processes design and optimization, the prediction of the phase behaviour of mixtures containing fatty esters, alcohols, glycerol and water is of utmost importance. In this work we show the capability of a A-UNIFAC to correlate and predict phase behaviour of these mixtures. This GE model is an extension of UNIFAC that explicitly includes association effects between groups based on the statistical Wertheim theory [1]. For the water-esters binary systems, the residual and association parameters have been previously estimated using low pressure VLE data [1]. The use of these parameters to predict liquid-liquid equilibrium results in good agreement with experimental information on binaries of water with acetic, octanoic or dodecanoic acids methyl esters. The association effect in methanol and glycerol are represented with the same hydrogen bonding hydroxyl groups (OH) with two associating sites, one group in methanol and three in glycerol. For the residual contribution, both molecules are considered as molecular groups (CH3OH and C3H8O3). The residual interaction parameters between CH3OH and C3H8O3 were obtained by fitting isothermal liquid-liquid equilibrium data on the ternary system dodecanoic acid methyl ester-methanol–glycerol [2]. The glycerol/paraffin (C3H8O3/CH2) and glycerol/ester (C3H8O3/CCOO) interaction parameters were estimated by fitting experimental data on liquid-liquid equilibrium and infinite dilution activity coefficients of the binary systems dodecanoic acid methyl ester-glycerol and hexanoic acid methyl ester-glycerol between 320-438 K [2]. A-UNIFAC with the final set of parameters is able to predict with good agreement experimental data on binary and ternary liquid-liquid equilibria of glycerol + methanol + fatty esters as well as infinite dilution activity coefficient for this system. References [1] O. Ferreira, E.A. Macedo, S.B. Bottini, Fluid Phase Equilib. 227 (2005) 165-176. [2] F.M. Korgitzsch, Study of Phase Equilibria as a Fundament for the Refinement of Vegetable and Animal Fats and Oils. Ph.D. Dissertation, TU Berlin, 1993.
- An association UNIFAC model for aqueous and alcohol solutions of sugarsPublication . Ferreira, Olga; Macedo, Eugénia A.In this work, a modified UNIFAC model [1] that explicitly takes into account association effects is applied to mixtures containing common sugars, alcohols and water. Following the same strategy adopted before [2], four residual groups were defined to represent the sugars family: the pyranose ring (PYR), the furanose ring (FUR), the osidic bond (-O-) and the hydroxyl ring group (OH ring) [2]. For the association term, a general two sites OH associating group is used to represent association effects in these solutions, allowing a straightforward extension to multicomponent mixtures. Correlation of both solvent activity properties (water activities, vapour pressures, boiling and freezing points of aqueous D-glucose and D-fructose solutions) and sugars (D-fructose, D-glucose and sucrose) solubility in water, ethanol and methanol give very good results. Satisfactory predictions are obtained for vapour-liquid equilibrium and solid-liquid equilibrium of ternary and quaternary mixtures of sugars in mixed solvents.
- An overview of teacher training in PortugalPublication . Ferreira, Olga; Silva, Adília T.; Barreiro, M.F.This paper presents an overview of teacher´s training in Portugal concerning initial teacher training (ITE), specialized training and in-service teacher training, as considered by the Portuguese legislation. A special emphasis was given to training in information and communication technologies (ICT) and to teaching of experimental sciences for primary school. Moreover, chemistry teacher’s training was contextualized in this scenario. Presently ITE corresponds to level 7 of the European Qualifications Framework (master degree). It is a career-long professional development, where research-based and in context practice are important features. Nevertheless the implicit valorisation of the teaching career arising from Bologna process implementation, a master degree is needed for all teaching levels; a lack of motivation to pursue teaching careers is generally noticed in Portugal as a consequence of the actual context of a surplus and unemployment among the new teachers. Following ITE, in-service training allows teachers to complement, deepen and update their knowledge and professional competences. This is an important measure for in-service long date teachers’ and particularly relevant for the ones that, following teacher career reorganization, had to readapt to new curricula and even new teaching subjects.
- Application of the GCA-EOS model to the supercritical processing of associating oil derivatives: fatty acids, alcohols and triglyceridesPublication . Ferreira, Olga; Pereda, Selva; Bottini, Susana B.; Brignole, Esteban A.Supercritical processes are of interest in the fatty oil industry for a variety of applications: extraction and refining, removal of pollutants, recovery of specialties, hydrogenation of oils and derivatives, etc. Typical process mixtures include heavy compounds and gases at near critical conditions. At high pressures these asymmetric systems present a complex multiphase behaviour, difficult to model. This complexity increases if some of the mixture components are able to self- and/or cross associate. In the present work, the group contribution with association equation of state (GCA-EoS) [3] is extended to represent high pressure phase equilibria in mixtures of supercritical gases (carbon dioxide, propane, ethane) with fatty oil derivatives, such as mono- and di-glycerides, fatty acids, alcohols, water and esters. Self- and cross association between associating groups present in these mixtures are considered. Satisfactory correlation and prediction of equilibrium data are obtained. The capacity of the model to follow the behaviour of solutions towards the limit of infinite dilution of the associating components is of particular importance.
- Application of the GCA-EoS model to the supercritical processing of fatty oil derivativesPublication . Ferreira, Olga; Macedo, Maria E.; Brignole, Esteban A.The group-contribution with association equation of state (GCA-EoS) is applied to represent high-pressure phase equilibria in mixtures of supercritical gases (carbon dioxide, propane) with fatty oil derivatives, such as mono- and di-glycerides, fatty acids and fatty acid esters. Association effects in these mixtures are described by a group-contribution approach using three different association groups: the hydroxyl group, the acid group and the ester group. Satisfactory predictions of vapor–liquid equilibria, liquid–liquid equilibria and c1 of binary and ternary mixtures of high-molecular weight triacyglycerides and their derivatives with carbon dioxide or propane are obtained. It is shown that the GCA-EoS is a powerful engineering tool for the design and optimization of extraction and fractionation processes of fatty oil derivatives with supercritical fluids.
- Application of the stretched simulated annealing method in the stability analysis of multicomponent systems using excess gibbs energy modelsPublication . Pereira, Ana I.; Ferreira, Olga; Pinho, SimãoIn this work, the Stretched Simulated Annealing Method was applied to identify the stationary points of the tangent plane distance function defined for the Gibbs energy. The classic excess Gibbs energy Non Random Two Liquid model was used for these studies in several multicomponent mixtures, for which specific numerical difficulties were shown. The results obtained by applying the methodology developed in this work were very satisfactory.
- The cation effect on the solubility of glycylglycine and N-acetylglycine in aqueous solution: Experimental and molecular dynamics studiesPublication . Pérez-Sánchez, Germán; Santos, Yoselyn Maria da Silva dos; Ferreira, Olga; Coutinho, João A.P.; Gomes, José R.B.; Pinho, SimãoThe specific interactions of ionswith biomolecules in aqueous solutions play a very important role in the life sciences and biotechnology. Thiswork aims to study the effect ofNaCl, KCl,NH4Cl, CaCl2 orMgCl2 on the solubility of two glycine derivatives, glycylglycine (a.k.a. diglycine) and N-acetylglycine, and to understand the nature of the interactions present on these systems. Experimentally, upon increasing the concentration of the salts, the solubility of N-acetylglycine decreased while the solubility of diglycine increased, with divalent cations inducing a greater salting-in on the solubility of diglycine thanmonovalent cations. For diglycine, the results frommolecular dynamics simulations correlate well with the salting-in effectwith interactions involving the cation and the carboxylate group, while for neutral N-acetylglycine the interactions between the chloride anion and the hydrogen atom of the carboxylic acid group, and between the carbonyl group of the peptide bond and the cation, can be exploited to describe the generalized salting-out effect.
- Characterization and Modeling of the Liquid Phase of Deep Eutectic Solvents Based on Fatty Acids/Alcohols and Choline ChloridePublication . Crespo, Emanuel A.; Silva, Liliana P.; Martins, Mónia A.R.; Fernandez, Luis; Ortega, Juan; Ferreira, Olga; Sadowski, Gabrielle; Held, Christoph; Pinho, Simão; Coutinho, João A.P.The solid-liquid equilibria phase diagrams of eight eutectic systems formed by choline chloride and fatty acids, or fatty alcohols, were measured to characterize the nonideality of the liquid phase of these systems, commonly reported in the literature as examples of type III deep eutectic solvents (DESs), and to evaluate the best modeling approaches to their description. Most of these systems are shown to present only slight deviations from ideal behavior, resulting from a fine balance of the hydrogen bonding between the hydroxyl/carboxylic groups with the chloride anion and the interactions present in the pure compounds. The phase diagrams measured were modeled with an associative equation of state (EoS) and a g E model. As an EoS, the perturbed-chain statistical associating fluid theory (PC-SAFT) was used, and this model was able to accurately describe the experimental data and to provide reliable estimates of the eutectic points using just a single binary temperature-dependent interaction parameter that often correlates with the acid/alcohol chain length. The performance of PC-SAFT was further compared with the g E model, a non-random two-liquid model (NRTL), and was found to provide a better description of the experimental data, especially for the more nonideal systems. Ultimately, the data gathered, and the molecular modeling, allowed the discussion of the behavior of fatty acids or fatty alcohols as hydrogen bond donors in choline chloride-based DESs.
- Chemistry education: the relevance of innovative pedagogical practices in the early yearsPublication . Rodrigues, Maria José; Ferreira, Olga; Barreiro, M.F.; Gonçalves, AdorindaConsensus exists among researchers and academics that science education, including chemistry education, is fundamental to the development of modern societies. Thus, investment becomes essential, from early years, in the education of informed citizens, prepared with scientific literacy competences and able to pursue an active, participative and responsible citizenship. In this context, school plays a major role and should provide chemistry education for all children. As such, it is necessary that teachers are able to meet this need and ensure the implementation of innovative practices, which, according to current guidelines, should be based in investigative activities of practical and experimental nature with a science-technology-society orientation, whose scientific contents are closely related to certain social phenomena (economics, politics and environment) and that meet the interests of children by helping them to explain and interpret the world around them. In this paper, we aim to present a review on the current guidelines for education in chemistry in the early years, that is, in pre-school and primary school, by applying a methodology based on practical and experimental work.