Programa de Pós-Graduação em Engenharia Química - PPGEQ/ITEC

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2308

O Programa de Pós-Graduação em Engenharia Química (PPGEQ) do Insituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA). Sendo aprovado pela CAPES / MEC em 1991, foi oficialmente iniciado em março de 1992.

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Agora exibindo 1 - 6 de 6

Acesso aberto (Open Access)
Aproveitamento da torta de dendê (elaeis guineenses) para a produção do acetato de celulose
(Universidade Federal do Pará, 2022-06-17) MORAES JUNIOR, Elio Ferreira de; ALMEIDA, Ossalin de; http://lattes.cnpq.br/7040173036131516; HTTPS://ORCID.ORG/0000-0003-3895-0952; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512
This work aimed to produce cellulose acetate (CA) from in natura palm kernel pie (TD) it was subjected to different chemical treatments: bleaching (TDB), alkaline (TDA) and alkaline followed by bleaching (TDAB). The CA was obtained from the different materials by homogeneous acetylation in the mass ratios: 1:5, 1:10 and 1:15 (acetic acid), 1:15 (acetic anhydride) and 1:0.1 (sulfuric acid). Reactions were carried out at room temperature under constant stirring (120 rpm, 24 h). The characterization was performed using scanning electron microscopy (SEM), infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H and 13C-NMR) techniques. The degree of substitution (GS) was determined by titration with 0.25 mol.L-1 sodium hydroxide solution, being confirmed by FTIR and 1H and 13C NMR with different GS. The CA synthesized from the combination of pre-treatments presented DS of 2.81 (TDAB5), 3.02 (TDAB10) and 3.07 (TDAB15), being, therefore, it characterized as cellulose triacetate, corresponding to the yield values (m/m) of 50.45%, 65.5% and 97.21%. By analyzing the results, TDAB15 was the best condition for obtaining cellulose acetate from palm kernel cake.
Acesso aberto (Open Access)
Dinâmica molecular de armazenamento de H2 em nanotubos de carbono sob ação de campo elétrico externo
(Universidade Federal do Pará, 2016-01-27) AIRES, Júlio Cesar Nunes; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512
Several thermodynamic properties were analyzed through computer simulations systems, in which we used a carbon nanotube a gas molecule (H2), the very low initial temperature of 10-3K order. This H2 molecule was chosen because of its properties are of great application in different branches of study, the physical sciences, chemical and biological. The H2 molecule is individually relaxed inside and outside the nanotube during simulations. Each system was under the influence of a uniform electric field parallel to the carbon nanotube and the thermal effect on the initial temperature in the simulations generating the evanescent effect. Due to the electric field, the molecule rotates at a low temperature in orbit about the carbon nanotube while increasing the value of the electric field permitted the variation of the radius of the orbit atoms. The calculated amounts were the following: kinetic energy, potential energy, the total energy, temperature variation in situ, the molar entropy and the mean radius of the orbit atoms. The data suggest the action of the electric field is sufficient only to generate the evanescent attractive potential and this system can be used as a sensor selector atoms.
Acesso aberto (Open Access)
Espectroscopias RAMAN, IR, DOS, UV-Vis e dicroismo circular das toxinas (anatoxina-a, anatoxina-as, cilindrospermopsina, homoanatoxina-a e saxitoxina) das algas.
(Universidade Federal do Pará, 2024-02-02) LOBATO, Marinaldo Carvalho; COSTA, José Francisco da Silva; http://lattes.cnpq.br/9492719731740641; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699
This thesis aims to understand Raman, IR, DOS, UV-Vis and Circular Dichroism spectroscopy of algal toxin molecules Anatoxin-a, Anatoxin-a(s), Cylindrospermopsin, Homoanatoxin-a and saxitoxin. The Gaussian 09W software was used for the theoretical calculations of energy minimization corresponding to the molecular mechanics method MM+ as well as the functional level B3lyp/6-311++G (d,p), used both in the optimization of the geometry and in the calculations of UV-Vis spectrometry, State Density and Circular Dichroism of non-solvent water molecules. The research results show relevant UV-Vis spectra, State Density, Circular Dichroism, Raman and Infrared in the elaboration of Tables that identify the modes of molecular vibrations of the aforementioned toxins, which lead to identifying the types of vibrations in each region contained in us specific wave compression intervals. Verify that each algal toxin presents a specific gap or that makes it possible to identify the one that presents the greatest reativity in relation to others (smallest gap) or greatest stability (largest gap). For the MEP (electrostatic potential map) it is possible to observe the region that presents the highest concentration of negative charges or that can be useful to identify regions of reaction between a toxin and a protein. The research was concluded considering an experimental comparison between the cylindrospermopsin toxin with graphical analyzes of two UV-Vis spectra that with a percentage of 0.5% of error, showing that based on B3lyp/6-311++G(d, p) selected was very significant for comparison between theoretical data in relation to experimental data.
Acesso aberto (Open Access)
O estudo da docagem e dinâmica molecular de potenciais fármacos: rodatina, scedapina C e cequinadolina A, utilizados no tratamento da SARS-COV-2
(Universidade Federal do Pará, 2022-05-06) LIMA, Antonio Sanderlei dos Santos; ALMEIDA, Ossalin de; http://lattes.cnpq.br/7040173036131516; HTTPS://ORCID.ORG/0000-0003-3895-0952; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512
Due to the study of new drugs to combat the SARS-COV-2 virus, which is causing the COVID-19 pandemic. In this work, we address the use of three drugs (Rhodatin, Scedapin C and Scequinadoline A) as possible inhibitors of SARS-CoV-2, as they have several interactive properties, showing potential to be used in the treatment of COVID19 disease. Molecular docking provided information about the affinity energy which was -8.186, -9.617, -7.866, -7.601, -7.527 kcal/mol, for the best conformations with Scequinadoline A. Molecular couplings and affinity energy showed the residues of the site macrostructures, and analyzed the electrostatic potential map to predict some promising candidates for virus antagonists. Molecular dynamics techniques were used, where the targets were the external structures of the virus, but specifically the envelope protein, main protease, Spike glycoprotein. Using the GROMACS 2021.2 modules, the results showed that the ligands have characteristics of interaction over time. Molecular dynamics provided values between 1.5 and 4.5Å for the mean square deviation of atomic positions. Among the results obtained through molecular dynamics, it was noted that the hydrogen bonds, when compared to the calculation of the square root of the mean square deviation, underwent a change in the amount of hydrogen bonds in the bonding process, according to the proximity of the ligand used to filter out unrealistic poses in the snap, and also improved the accuracy of binding energy calculation. Analysis of molecular couplings showed that the S-gly active site residues strongly interacted with the three drugs. The reuse of these drugs in the fight against SARSCoV-2 may be candidates via virus antagonists, which if confirmed through experimental approaches, can contribute to the resolution of the global crisis of the COVID-19 pandemic.
Acesso aberto (Open Access)
Interações de Quantum Dot com estruturas externas de vírus Nipah utilizando docking e dinâmica molecular
(Universidade Federal do Pará, 2023-01-30) ALMEIDA, Aguinaldo Pantoja de; OLIVEIRA, Mozaniel Santana de; http://lattes.cnpq.br/0810227136654245; HTTPS://ORCID.ORG/0000-0002-4076-2443; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699; https://orcid.org/0000-0002-9730-3512
Performing the interaction of the outermost protein of the Nipah virus with fourteen structures with possible potential for the emission of quantum dots, using anchoring and molecular dynamics, using molecular docking platforms: CB Docking, Swiss DOCK, AutoDock Vina 4.2.6 to perform a comparison of results explaining the best values, in addition to using Gromacs 2022 to make ligand trajectories in relation to time. The mostly hydrophobic complexes at the receptor binding site. The tolerance energy results tolerated the partial loads of the tips which showed better stability, the RMSD results also respected this premise. Thus, the set formed by combining proteins with a quantum dot has the potential to more efficiently adsorbing of the protein components of the virus. Molecular dynamics and docking studies and verification of binding energy revealed strong and stable binding between para QD K and QD-G and QD-F with the macrostructure of NIPAH virus. It was established in the docking studies, that the binders have emission energy scores of -13,658 kcal/mol, -13.6 kcal/mol, -13.9 kcal/mol, for K, G and F respectively. The same result was applied in the Gibbs free energy verification study with values for F of 239.00 kcal/mol, G of 246.65 kcal/mol and K of 259.52 kcal/mol.
Acesso aberto (Open Access)
Propriedades termodinâmicas de propanóis na fase gasosa via DFT
(Universidade Federal do Pará, 2021-05-03) LOPES, Franklin dos Santos; CHAVES NETO, Antônio Maia de Jesus; http://lattes.cnpq.br/3507474637884699
The main objective of this study is to evaluate the effect of the thermodynamic properties of propanols propan-1-ol, propan-2-ol and their isomers 2- methylpropan-1-ol and 2-methylpropan-2-ol in addition to elaborating a proposal for mixtures with fuels, gasoline, diesel, and kerosene-based on the Functional Density Theory to determine thermodynamic properties, such as specific molar heat at constant pressure, entropy, Gibbs free energy, a variation of the formation enthalpy for calculating the heat of combustion. The excited state of the propanols and their isomers, applied to their energy figures transferred by the functional hybrid of the B3LYP structures, in the bases 6–311 ++ g (d, p) and 6-31g (d) were simulated using the software package Gaussian 09W and the semi-empirical method PM3. To obtain the physical properties of the chemical reactivity in the gas phase of each component and its combustible isomers, the temperature range of 0.5K - 1500K was used at a constant pressure of 1atm and in a vacuum. The addition of propane and its isomers in the combustion phase provided a greater energy balance as a whole, with 2-methylpropan-1-ol and 2-methylpropan-2-ol generating 13.38 and 13.88 KJ / ga more of gain energy per unit mass than ethanol (22.73 KJ / g) and methanol (12.70 KJ / g), the progressive increase of fractions 10%, demonstrates that propan-1-ol with 33.49 KJ / g and propan-2-ol 33.53 KJ / g, obtained the highest energy losses when compared to gasoline, which reached 13.81 and 13.77 KJ / g respectively in pressures, temperature patterns. TheX combustion of propan-1-ol was the lowest in all events over fractions in the case of diesel fuel 11.31 KJ / g and kerosene 12.71 KJ / g.

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