Fernando Cunha Peixoto
@ime.eb.br
Seção de Engenharia Química
Instituto Militar de Engenharia
EDUCATION
Chemical Engineering - 1994 - UFRJ/Brazil
M. Sc. Chemical Engineering - 1996 - UFRJ/Brazil
D. Sc. Chemical Engineering - 1999 - UFRJ/Brazil
RESEARCH, TEACHING, or OTHER INTERESTS
Chemical Engineering
Scopus Publications
Scopus Publications
I.F. Pinheiro, H.L. Serrano, L.A. Sphaier, F.C. Peixoto, and V.N.H. Silva
Elsevier BV
José Daniel Langendorf da Silva, Rodrigo Leonard Barboza Rodrigues, Rogério Rosato, Maurício Ferrapontoff Lemos, Letivan Mendonça Filho, Tanos Celmar Costa França, and Fernando Cunha Peixoto
Wiley
AbstractNitrocellulose‐based propellants undergo natural (and inevitable) autocatalytic degradation reactions. The presence of a stabilizer is essential to avoid and reduce the degradation reactions by capturing the NOx molecules. Traditional stabilizers, such as diphenylamine, and ethylcentralite, react with NOx through their amine and/or amide groups, leading to n‐nitroso groups, which are known to have carcinogenic, mutagenic and reprotoxic properties. Molecules that are not prone to form by‐products containing nitrosamines have been studied as substitutes, such as guaiacol and curcumin. However, the aromatic rings on these molecules have their acidity augmented when capturing the NOx groups and, paradoxically, increasing hydrolysis rates. In order to find a solution for the problem, we evaluated the use of essential oils containing terpenes and/or phenolic compounds to introduce a buffering capacity. Several propellant formulations with those compounds were subjected to traditional stability tests (German, Bergman–Junk and Storage tests), Pressure Vacuum Stability Test and Heat Flow Microcalorimetry. Finally, industrial batches were produced for the evaluation of real (ballistic) performance. Results indicated that the usage of essential oils increases stability properties not only through a sum of effects, but also in a synergistic way. Ballistic results were also adequate.
Rafaella Silva Aredes, Fernando Cunha Peixoto, Leandro Alcoforado Sphaier, Vinicius Nunes Henrique Silva, Lucas Mattos Duarte, and Flávia Ferreira de Carvalho Marques
Elsevier BV
Luciana Amorim da Silva, Ana Carolina Marotti Dias, Hector Gabriel Teixeira Volskis, José Daniel Langendorf da Silva, Aline Cardoso Anastacio, and Fernando Cunha Peixoto
FapUNIFESP (SciELO)
Several aspects make nitrocellulose based powders adequate as a solid propellant for rockets and missiles and the prefe rable propellant to be used in firearms and artillery: it produces less smoke and less fouling than other propellants; its burning rate shows a well-defined relation to pressure and the composition of the gaseous mixture resulting from its decomposition by burning can be predicted with relatively high levels of accuracy. This last feature, if coupled with adequate thermodynamic models, leads to a reliable framework for the simulation of internal ballistics and, ultimately, to an efficient design. Some simpler models use an ideal gas approach, which is obviously not adequate, and some others perform corrections based on the Virial E quation of S tate for sake of algebraic simplicity. This work employs the Peng-Robinson equation of state to model the pressure-volume-temperature (PVT) behavior of the gases produced during the burning reaction, once it is known to be accurate in the high pressures obtained inside combustion chambers. The results were compared to experimental data obtained in a closed vessel device and showed that the Peng-Robinson equation of state could predict the chamber pressure with higher accuracy.
André Von‐Held Soares, Housam Binous, Fernando Cunha Peixoto, and Ahmed Bellagi
Wiley
AbstractAn important part of the education of chemical engineers involves the design and assessment of heterogeneous catalytic reactions. They pose fundamental phenomena and constitute invaluable industrial processes. Progressing in this field, especially in graduate‐level courses, entails solving nonlinear differential equations systems, which can only be achieved by using efficient and reliable numerical techniques. In this work, we solve nonisothermal one‐dimensional reaction‐diffusion BVP considering convection in the boundary conditions, by applying orthogonal collocation and arc‐length continuation. Particularly, we predict the effectiveness factor as a function of the Thiele modulus for the main three particle geometries: plane slab, cylinder, and sphere. For chemical engineering students, such problems are at the zenith of the discipline, and the results of such calculations can elucidate basic and advanced concepts of mass and heat transfer as well as chemical reaction engineering. Both Chebyshev and shifted Legendre polynomials were used to transform the boundary value problem into a set of algebraic nonlinear equations. In addition, we also compare our findings against the available analytic solutions whenever possible. Codes in Scilab, Matlab®, and Mathematica© were developed for the solution of such problems and are available in the Supporting Information. There are two possible approaches to compute effectiveness factors: (a) integration as per definition versus (b) differentiation and nonlinear system. It is demonstrable that software performance is dependent on the approach, and that the differentiation approach yields better results.
Rodrigo L. B. Rodrigues, Ana Paula da Silva, Rogério Rosato, Maurício F. Lemos, Fernando C. Peixoto, Tanos C. C. França, and Letivan G. Mendonça Filho
Springer Science and Business Media LLC
Karla M. Boaventura, Fernando C. Peixoto, Heloísa L.S. Fernandes, and Fernando L.P. Pessoa
Elsevier BV
Rodrigo Leonard Barboza Rodrigues, Pedro Augusto Gomes Buitrago, Nami Lavigne Nakano, Fernando Cunha Peixoto, Maurício Ferrapontoff Lemos, Tanos Celmar Costa França, and Letivan Gonçalvez Mendonça Filho
Informa UK Limited
ABSTRACT This research evaluates the feasibility of replacing diphenylamine (DPA) with the natural product curcumin as a stabilizer in samples of nitrocellulose-based (NC-based) propellants. The stability analysis was performed using heat flow calorimetry, as described in STANAG-4582, as well as the most traditional stability testing protocols: the German test, Bergmann–Junk test, and the Storage test. Ballistic parameters were evaluated using a closed vessel ballistic test and samples underwent Scanning Electron Microscopy (SEM). Also, the Pressure Vacuum Stability Test (PVST), Differential Scanning Calorimetry (DSC), and Isothermal Thermogravimetry (TG) to evaluate the homogeneity, stability, and compatibility with NC were performed. The ballistic parameters were evaluated using a closed vessel ballistic test. All samples of propellants stabilized with curcumin passed the stability test criteria performed in this research, with better scores than the propellant sample stabilized with DPA, which was used as a reference. However, the estimation of ballistic parameters indicated that the deflagration of the propellant stabilized with curcumin exhibits some delay when compared to the reference sample, which can be easily overcome by adjusting the propellant grain dimensions, especially the thickness. Finally, an HPLC analysis method was developed to identify and characterize this new Single-Based (SB) propellant stabilizer. This method was shown to be effective, fast, accurate, and adequate to comply with the stability criteria proposed by the AOP-48 standard, especially because of the depletion of the stabilizer concentration after artificial aging. We believe that our results are promising and support the proposal that curcumin can replace DPA as a stabilizer for SB propellants.
Vicente A. Oliveira, Alexander C. Carneiro, Alexandre B. Dos Santos, Andrés Pablo L. Barbero, Fernando C. Peixoto, and Vinicius N. H. Silva
Optica Publishing Group
Etched fiber Bragg gratings (EFBGs) have been widely employed for refractive index (RI) measurements that can be used to monitor sugar consumption during the fermentation of alcoholic beverages. EFBGs are obtained by removing the cladding of a fiber Bragg grating, which is traditionally performed by a chemical attack with hydrogen fluoride, an extremely hazardous corrosive substance that causes severe wounds and even death. To overcome such drawbacks, this technical note presents a simple, practical, and low cost method for the diameter reduction of single mode optical fibers by mechanical polishing, employing a small scale computer numerical control device and an ad hoc 3D-printed rod. The sensor probe obtained was tested using sucrose aqueous solutions with RIs between 1.333 and 1.394, measured in an Abbe refractometer. The results show a linear shift of the Bragg wavelength with respect to RI with a correlation of 0.928.
Rafaella Silva Aredes, Fernando Cunha Peixoto, Leandro Alcoforado Sphaier, and Flávia Ferreira de Carvalho Marques
Elsevier BV
Alexandre Santuchi da Cunha, Fernando Cunha Peixoto, and Diego Martinez Prata
Computers and Chemical Engineering Elsevier BV
Vicente A. de Oliveira, Andres Pablo L. Barbero, Leandro A. Sphaier, Alexandre B. dos Santos, Fernando C. Peixoto, and Vinicius N. H. Silva
Institute of Electrical and Electronics Engineers (IEEE)
A refractometer based on an etched fiber Bragg gratings (EFBGs) sensor has been developed for monitoring beer fermentation in real time. The sensor was calibrated using synthetic solutions composed of water, maltose, and ethanol with alcohol by volume (ABV) ranging from 4.0% to 12.0% and Brix (sugar content) varying from 5% to 25%. Calibration results showed that the EFBG sensor responds with high sensitivity even to minor density variations less than 0.5 Brix ± 0.03 Brix in a quasi-linear monotonic fashion with respect to sugar and ethanol concentration, which allowed fitting an empirical model with good adherence to experimental data (low model variance) and with well-defined parameters (parameters covariance matrix with elements exhibiting small absolute values). Finally, the developed sensor was tested in a typical fermentation scenario. A rigorous material balance framework was established to relate the fit calibration model to actual density and alcohol content in real time, which is of assistance for process control strategies. As the proposed sensor can be fit in fermentation vessels for real-time (online) fermentation monitoring, it becomes a technological improvement to traditional offline measurements in terms of both biosafety and process control.
Ivi Nascimento, Lucas Calado, Maria Eduarda Duncan, Bruna Trindade, Leandro Sphaier, Vinicius Silva, and Fernando Peixoto
Elsevier BV
L.S. Calado, A.L.F. Lacerda, S.B. Fiaux, L.A. Sphaier, V.N.H. Silva, and F.C. Peixoto
Elsevier BV
Mateus A. Gonçalves, Lizandro S. Santos, Fernando C. Peixoto, and Teodorico C. Ramalho
Wiley
Gustavo N. Oliveira, Natane C. Barbosa, Felipe C. Araújo, Pedro H. G. Souza, André V. H. Soares, Fernando C. Peixoto, José W. M. Carneiro, and Fabio B. Passos
Springer Singapore
I.F. Pinheiro, H.L. Serrano, L.A. Sphaier, F.C. Peixoto, and V.N.H. Silva
Elsevier BV
Lizandro de Sousa Santos, Kaio Magno Ferreira de Souza, Marina Ribeiro Bandeira, Víctor Rolando Ruiz Ahón, Fernando Cunha Peixoto, and Diego Martinez Prata
Elsevier BV
Mateus A. Gonçalves, Lizandro S. Santos, Fernando C. Peixoto, Elaine F. F. da Cunha, Telles C. Silva, and Teodorico C. Ramalho
Wiley
Mateus A. Gonçalves, Lizandro S. Santos, Diego M. Prata, Fernando C. Peixoto, Elaine F. F. da Cunha, and Teodorico C. Ramalho
Springer Science and Business Media LLC
Marco André Abud Kappel, Fernando Cunha Peixoto, Gustavo Mendes Platt, Roberto Pinheiro Domingos, and Ivan Napoleão Bastos
Elsevier BV
Mateus A. Gonçalves, Elaine F.F. da Cunha, Fernando C. Peixoto, and Teodorico C. Ramalho
Elsevier BV
Mateus A. Gonçalves, Fernando C. Peixoto, Elaine F.F. da Cunha, and Teodorico C. Ramalho
Elsevier BV