Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
The energetics of the phenolic O−H bond in a series of 2- and 4-HOC6H4C(O)Y (Y = H, CH3, CH2CH═CH2, C≡CH, CH2F, NH2, NHCH3, NO2, OH, OCH3, OCN, CN, F, Cl, SH, and SCH3) compounds and of the intramolecular O···H hydrogen bond in 2-HOC6H4C(O)Y, was investigated by using a combination of experimental and theoretical methods. The standard molar enthalpies of formation of 2-hydroxybenzaldehyde (2HBA), 4-hydroxybenzaldehyde (4HBA), 2′-hydroxyacetophenone (2HAP), 2-hydroxybenzamide (2HBM), and 4-hydroxybenzamide ( ...
Tópico(s): Analytical Chemistry and Chromatography
2008 - American Chemical Society | The Journal of Physical Chemistry A
Miroslav Leskiv, Carlos E. S. Bernardes, Manuel E. Minas da Piedade, José N. Canongia Lopes,
The energetics of aqueous solutions of the ionic liquid (IL) 1-ethyl-3-methylimidazolium ethylsulfate in the concentration range m < 165 mol·kg(-1) was analyzed on the basis of the enthalpies of solution of the IL in water (Δ(sol)H(m)) and the enthalpies of dilution (Δ(dil)H(m)) of solutions with different IL concentrations. The data were both obtained experimentally, by calorimetry, and theoretically, by using Molecular Dynamics (MD) simulations. Particular attention was given to the low-concentration ...
Tópico(s): Thermodynamic properties of mixtures
2010 - American Chemical Society | The Journal of Physical Chemistry B
Carlos E. S. Bernardes, Manuel E. Minas da Piedade, Luı́sa M.P.F. Amaral, Ana I.M.C. Lobo Ferreira, Manuel A.V. Ribeiro da Silva, Hermı́nio P. Diogo, Benedito J. Costa Cabral,
The energetics of the C-F, C-Cl, C-Br, and C-I bonds in 2-haloethanols was investigated by using a combination of experimental and theoretical methods. The standard molar enthalpies of formation of 2-chloro-, 2-bromo-, and 2-iodoethanol, at 298.15 K, were determined as Delta(f)H(degree)m(CH2CH2OH, l) = -315.5 +/- 0.7 kJ.mol-1, Delta(f)H(degree)mBrCH2CH2OH, l) = -275.8 +/- 0.6 kJ.mol-1, Delta(f)H(degree)m(ICH2CH2OH, l) = -207.3 +/- 0.7 kJ.mol-1, by rotating-bomb combustion calorimetry. The corresponding standard molar ...
Tópico(s): Atmospheric chemistry and aerosols
2007 - American Chemical Society | The Journal of Physical Chemistry A
Carlos E. S. Bernardes, Manuel E. Minas da Piedade, José N. Canongia Lopes,
Several structural features of aqueous solutions of the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate were analyzed in the entire concentration range using molecular dynamics simulation results. Different analysis tools developed in-house were applied to describe the size and connectivity of different water and ion aggregates as a function of the solution concentration. Four concentration ranges-x(H(2)O)<0.5, 0.5<x(H(2)O)<0.8, 0.8<x(H(2)O) 0.95-with four distinct structural regimes--isolated ...
Tópico(s): Electrochemical Analysis and Applications
2011 - American Chemical Society | The Journal of Physical Chemistry B
Peter Mulder, Olga Mozenson, Shuqiong Lin, Carlos E. S. Bernardes, Manuel E. Minas da Piedade, Ana Filipa L.O.M. Santos, Manuel A. V. Ribeiro da Silva, Gino A. DiLabio, Hans‐Gert Korth, K. U. Ingold,
There are conflicting reports on the origin of the effect of Y substituents on the S-H bond dissociation enthalpies (BDEs) in 4-Y-substituted thiophenols, 4-YC(6)H(4)S-H. The differences in S-H BDEs, [4-YC(6)H(4)S-H] - [C(6)H(5)S-H], are known as the total (de)stabilization enthalpies, TSEs, where TSE = RSE - MSE, i.e., the radical (de)stabilization enthalpy minus the molecule (de)stabilization enthalpy. The effects of 4-Y substituents on the S-H BDEs in thiophenols and on the S-C BDEs in phenyl thioethers ...
Tópico(s): Thermal and Kinetic Analysis
2006 - American Chemical Society | The Journal of Physical Chemistry A
Joana Vitorino, Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
A general strategy to determine enthalpies of formation of protic ionic liquids, based solely on enthalpy of solution measurements, was conceived and tested for 1-methylimidazolium ethanoate, leading to ΔfHom{[Hmim][O2CCH3], 1} = −(425.7 ± 1.2) kJ mol−1. This result in conjunction with the enthalpy of formation of gaseous 1-methylimidazole (mim) proposed in this work, ΔfHom(mim, g) = 126.5 ± 1.1 kJ mol−1, and ΔfHom(CH3COOH, g) taken from the literature, allowed the calculation of the enthalpy of the vaporisation ...
Tópico(s): Phase Equilibria and Thermodynamics
2012 - Royal Society of Chemistry | Physical Chemistry Chemical Physics
Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
The preparation of polymorphs and solvates and the characterization of their stability domains have received considerable attention in recent years, due to the importance of these studies for fundamental research and for the production of new materials for task-specific applications. In this work, the selective and reproducible crystallization of different solid forms of 4′-hydroxyacetophenone (HAP) from water was investigated, through the determination of a temperature–concentration (T–cHAP) phase ...
Tópico(s): Surfactants and Colloidal Systems
2012 - American Chemical Society | Crystal Growth & Design
Abhinav Joseph, Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
The molar heat capacity of pyridine-3-carboxylic acid (nicotinic acid) for T = (296 to 531) K was investigated by differential scanning calorimetry (DSC) and Calvet-drop microcalorimetry. The measurements extended up to the liquid range and also covered the interval where a reversible and fast solid-solid (cr II → cr I) phase transition occurs. The molar enthalpies and entropies of that phase transition and of fusion were obtained as Ttrs = (455.0 ± 0.2) K, ΔtrsHmo = (0.90 ± 0.10) kJ ⋅ mol−1, ΔtrsSmo = (1.98 ± 0.22) J ⋅ K− ...
Tópico(s): Thermodynamic properties of mixtures
2012 - Elsevier BV | The Journal of Chemical Thermodynamics
Carlos E. S. Bernardes, Manuel Matos Lopes, José R. Ascenso, Manuel E. Minas da Piedade,
Crystallization is indisputably one of the oldest and most widely used purification methods. Despite this fact, our current understanding of the early stages of crystallization is still in its infancy. In this work dynamic light scattering and proton nuclear magnetic resonance were used to investigate the changes occurring in 4′-hydroxyacetophenone colloidal particles, as they form in a supersaturated aqueous solution and evolve toward anhydrous or hydrate materials during a cooling crystallization ...
Tópico(s): Spectroscopy and Quantum Chemical Studies
2014 - American Chemical Society | Crystal Growth & Design
Ricardo G. Simões, Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
A procedure for the selective and reproducible preparation of the two known 4-hydroxybezaldehyde polymorphs was developed, based on the investigation of their relative stabilities by differential scanning calorimetry and solubility studies. From the obtained results, the stability domains of the two forms could be quantitatively represented in a ΔfGm°–T phase diagram. The system was found to be enantiotropic: form II is more stable than form I up to 277 ± 1 K; above this temperature, the stability ...
Tópico(s): Analytical Chemistry and Chromatography
2013 - American Chemical Society | Crystal Growth & Design
Carlos E. S. Bernardes, Manuel E. Minas da Piedade, José N. Canongia Lopes,
A molecular dynamics simulation study of the two known polymorphs of 4′-hydroxyacetophenone (HAP; form I, monoclinic; form II, orthorhombic) is described. The modeling of the lattice energetics was found to be particularly sensitive to the atomic point charge (APC) selection method, to the number of molecules in the asymmetric unit (Z′), and to the flexibility allowed for the molecules. In order to improve the quality of the APCs, a new strategy that attempts to simulate the polarizability effects ...
Tópico(s): Molecular spectroscopy and chirality
2012 - American Chemical Society | The Journal of Physical Chemistry B
Ricardo G. Simões, Hermı́nio P. Diogo, Ana Dias, M. Conceição Oliveira, Carlos Cordeiro, Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
Simvastatin (SV) is a widely used drug for the treatment of hypercholesterolemia in humans. Nevertheless, serious efforts are still being made to develop new SV formulations with, for example, improved tabletability or bioavailability properties. These efforts frequently involve heating the compound well above ambient temperature or even fusion. In this work, the thermal stability of solid SV under different atmospheres was investigated by using isothermal tests in glass ampules, differential scanning ...
Tópico(s): Plant biochemistry and biosynthesis
2013 - Elsevier BV | Journal of Pharmaceutical Sciences
Cátia S. D. Lopes, Filipe Agapito, Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
The thermochemistry of 4-HOC6H4COR (R = H, CH3, C2H5, n-C3H7, n-C4H9, n-C5H11, and n-C6H13) compounds was investigated using enthalpy of vaporization/sublimation measurements by Calvet-drop microcalorimetry and W1-F12 and CCSD(T)-F12 ab initio calculations. Based on the obtained results, standard (p° = 1 bar) molar enthalpies of formation in the solid, ΔfHmo(cr), and gaseous, ΔfHmo(g), states, at T = 298.15 K, could be derived for the complete series of compounds. An excellent linear correlation was found ...
Tópico(s): Thermodynamic properties of mixtures
2016 - Elsevier BV | The Journal of Chemical Thermodynamics
Produção Nacional
Revisado por pares
Renata Junqueira Moll Bernardes, Edson Marchiori, Paulo Manuel de Barros Bernardes, Maria Beatriz Albano Monzo Gonzaga, Luiz Carlos Simões,
Aims: Our purpose was to assess the value of magnetic resonance angiography as a non-invasive alternative to catheterization in the evaluation of patients with tetralogy of Fallot, including those with pulmonary atresia. Methods and results: We evaluated prospectively, using magnetic resonance angiography, 30 patients, aged from 1 to 18 years, 15 with tetralogy of Fallot and pulmonary stenosis, and 15 with pulmonary atresia. The studies obtained using magnetic resonance provided adequate visualization ...
Tópico(s): Aortic Disease and Treatment Approaches
2006 - Cambridge University Press | Cardiology in the Young
Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
Tópico(s): Chemical and Physical Properties in Aqueous Solutions
2010 - Springer Science+Business Media | Journal of Thermal Analysis and Calorimetry
Joana Vitorino, Filipe Agapito, Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
The standard molar enthalpies of vaporization, ΔvapHmo, of 1-ethyl, 1-butyl, and 1-octylimidazole, at T = 298.15 K, were measured by Calvet-drop microcalorimetry. The values determined, together with results of high-level ab initio calculations (W1-F12 and CCSD(T)-F12) and published ΔvapHmo data were used to obtain the enthalpies of formation in the gaseous and liquid states of 1-alkylimidazole compounds ranging from 1-methylimidazole to 1-dodecylimidazole. Structure-energetics trends related to the ...
Tópico(s): Thermal and Kinetic Analysis
2014 - Elsevier BV | The Journal of Chemical Thermodynamics
Produção Nacional
Revisado por pares
Vinicius Carbone Bernardes de Oliveira, Carlos Manuel de Assis Silva, Leonardo Fonseca Borghi, Ismar de Souza Carvalho,
This study presents a facies characterization, facies succession and conceptual depositional model of the Coqueiros Formation, Lower Cretaceous of Campos Basin, based on core analyses of two wells. WELL-1 is a shallow water drilling located at south of Campos Basin within the Badejo structural high, and WELL-2 is an ultra deep water drilling located at north, over the “External High”. Ten carbonate facies, three siliciclastic facies, two magnesium clay mineral rich facies and two hybrid facies were ...
Tópico(s): Geological and Geochemical Analysis
2019 - Elsevier BV | Journal of South American Earth Sciences
Carlos E. S. Bernardes, Abhinav Joseph, Manuel E. Minas da Piedade,
Differential Scanning Calorimetry (DSC) is a widely accessible and versatile method for the determination of the heat capacities of organic materials as a function of temperature. In routine use, it is typically possible to obtain results with an accuracy better than 3 %. However, to achieve this level of accuracy, careful optimization of the experimental procedure for a specific apparatus must be performed. Using benzoic acid as a test substance, this work highlights some practical aspects of heat ...
Tópico(s): Thermal and Kinetic Analysis
2020 - Elsevier BV | Thermochimica Acta
Elsa Gonçalves, Carlos E. S. Bernardes, Hermı́nio P. Diogo, Manuel E. Minas da Piedade,
The standard molar enthalpies of formation and sublimation of crystalline (monoclinic, space group P21/c) nicotinic acid (NA), at 298.15 K, were determined as ΔfHm°(NA, cr) = −344.7 ± 1.2 kJ·mol−1 and ΔsubHm°(NA) = 112.1 ± 0.5 kJ·mol−1 by using combustion calorimetry, drop-sublimation Calvet microcalorimetry, and the Knudsen effusion method. The experimental determinations were all based on a sample of NIST Standard Reference Material 2151, which was characterized in terms of chemical purity, phase purity, ...
Tópico(s): Analytical Chemistry and Chromatography
2010 - American Chemical Society | The Journal of Physical Chemistry B
João Pedro Bernardes, Fernando Ferreira, António Manuel Dinis Ribeiro Marques, Mafalda Nogueira,
This paper contributes to a consolidation of the field by narrowing down the gap between sustainable consumption "attitudes/intentions" and actual consumption "behaviour". The adopted methodology is based on a systematic literature review with an initial sample of more than 1000 publications, this paper considers the following inclusion and exclusion criteria throughout the review: research scope, conceptualisation of the terms (e.g. "Sustainable consumption"; "Ethical consumption"; "Green consumption"; " ...
Tópico(s): Sustainable Supply Chain Management
2018 - IOP Publishing | IOP Conference Series Materials Science and Engineering
Miroslav Leskiv, Carlos E. S. Bernardes, Manuel E. Minas da Piedade,
An electrically calibrated and computer-controlled apparatus based on the LKB 10700-1 flow microcalorimeter was set up and tested by determining the enthalpies of dilution of aqueous solutions of sucrose and HCl at 298.15 K. The obtained results are in good agreement with the corresponding reference values recommended in the literature. The quality of the calorimetric signal in terms of noise, linearity and baseline drift, and the instrument time constant were analyzed. Also investigated were the ...
Tópico(s): Chemical and Physical Properties in Aqueous Solutions
2009 - IOP Publishing | Measurement Science and Technology
Arthur Bernardes Cecílio Filho, Víctor Manuel Vergara Carmona, Alécio Aparecido Schiavon,
Single-head broccoli production has been increasingly popular among Brazilian olericulture farmers, although there is still little information regarding its nutrition. The aim of this paper was to study dry matter and nutrient uptake rate in single-head broccoli. The experiment was conducted during the period from March to May 2006 in Itatiba, SP, Brazil. The experimental design was completely randomized, with four repetitions. Plant samples were taken at 15, 25, 35, 45, 55, 65 and 75 days after ...
Tópico(s): Growth and nutrition in plants
2017 - | Científica
Carlos E. S. Bernardes, M. Fátima M. Piedade, Manuel E. Minas da Piedade,
A new polymorph of 4′-hydroxyacetophenone (form I, monoclinic, P21/c, Z′ = 1) was isolated and characterized. The structural differences between this phase and the previously known one (form II, orthorhombic, P212121, Z′ = 2) were investigated by X-ray diffraction. The two polymorphs exhibit distinct packing features and, at the molecular level, they seem to differ by the relative conformations of the OH and C(O)CH3 groups. The stability domains of the two phases from 298.15 K to the fusion temperature ...
Tópico(s): Crystallization and Solubility Studies
2008 - American Chemical Society | Crystal Growth & Design
Carlos E. S. Bernardes, José N. Canongia Lopes, Manuel E. Minas da Piedade,
A previously developed OPLS-based all-atom force field for organometallic compounds was extended to a series of first-, second-, and third-row transition metals based on the study of M(CO)(n) (M = Cr, Fe, Ni, Mo, Ru, or W) complexes. For materials that are solid at ambient temperature and pressure (M = Cr, Mo, W) the validation of the force field was based on reported structural data and on the standard molar enthalpies of sublimation at 298.15 K, experimentally determined by Calvet-drop microcalorimetry ...
Tópico(s): Crystallography and molecular interactions
2013 - American Chemical Society | The Journal of Physical Chemistry A
João Pedro Bernardes, António Manuel Dinis Ribeiro Marques, Fernando Ferreira, Mafalda Nogueira,
This paper explores the creation of an innovative clothing rental service, that is inspired by the ‘slow fashion movement’, and that focuses on the question: “are people willing to use second-hand clothing and/or leased when travelling?”. This is a rental service for the day-to-day and also business clothing. The creation and development of this service was possible through the use of a design thinking methodology: the 9 steps framework by Kees Dorst. Regarding its validation, it was achieved with ...
Tópico(s): Crafts, Textile, and Design
2018 - | Industria Textila
Produção Nacional
Revisado por pares
Abhinav Joseph, Joana S. Rodrigues Alves, Carlos E. S. Bernardes, M. Fátima M. Piedade, Manuel E. Minas da Piedade,
Different 5-hydroxynicotinic acid tautomers were selectively captured through solvate formation. The selectivity is lost once the memory of solvation is erased by removing the solvent from the crystal lattice.
Tópico(s): Chemical Synthesis and Analysis
2019 - Royal Society of Chemistry | CrystEngComm
Carlos E. S. Bernardes, M. Fátima M. Piedade, Manuel E. Minas da Piedade,
A new hydrate of 4′-hydroxyacetophenone (HAP), triclinic, space group P1̅, was isolated and characterized. Both the structure determination by single crystal X-ray diffraction at 150 K and the results of thermogravimetry analysis carried out in the temperature range 263−363 K indicated the H2O/HAP molar ratio to be 1.5. The water molecules line up in chains that reside in lattice channels (channel hydrate) and are sustained by OH···O hydrogen bonds. The chains also interact with the OH (donor) and ...
Tópico(s): Chemical and Physical Properties in Aqueous Solutions
2010 - American Chemical Society | Crystal Growth & Design
Carlos E. S. Bernardes, Luı́s M. N. B. F. Santos, Manuel E. Minas da Piedade,
A new electrically calibrated calorimetric system to measure heat capacities of solids has been designed and tested by determining the heat capacity of sapphire and benzoic acid in the temperature range 298–393 K. Comparison of the obtained results with recommended adiabatic calorimetry data showed that the maximum and average absolute deviations were 3.3% and 1.6%, respectively. The technique provides a convenient alternative to routine heat capacity determinations by DSC, since the experiments ...
Tópico(s): Thermal and Kinetic Analysis
2006 - IOP Publishing | Measurement Science and Technology
Ricardo G. Simões, Carlos E. S. Bernardes, Hermı́nio P. Diogo, Filipe Agapito, Manuel E. Minas da Piedade,
The study of structure–energetics relationships for active pharmaceutical ingredients has received considerable attention in recent years, due to its importance for the effective production and safe use of drugs. In this work the widely prescribed cholesterol-lowering drug simvastatin was investigated by combining experimental (combustion calorimetry and differential scanning calorimetry, DSC) and computational chemistry (quantum chemistry and molecular dynamics calculations) results. The studies ...
Tópico(s): Metabolomics and Mass Spectrometry Studies
2013 - American Chemical Society | Molecular Pharmaceutics
Carlos E. S. Bernardes, Laura M. Ilharco, Manuel E. Minas da Piedade,
In this work we show that the two known polymorphs of 4′-hydroxyacetophenone (form I, monoclinic, P21/c, Z′/Z = 1/4; form II, orthorhombic, P212121, Z′/Z = 2/8) can be clearly distinguished by diffuse reflectance infrared Fourier-transform infrared (DRIFT) spectroscopy. The experimental studies were complemented by density functional theory calculations (DFT) carried out at the B3LYP/cc-pVTZ level of theory on the E and Z molecular conformers present in the solid forms I and II, respectively. Comparison ...
Tópico(s): Nonlinear Optical Materials Research
2013 - Elsevier BV | Journal of Molecular Structure