Este estudo centra-se na análise de um único diploma legal, o que versa, em Portugal, a responsab... more Este estudo centra-se na análise de um único diploma legal, o que versa, em Portugal, a responsabilidade do produtor e do distribuidor por produtos defeituosos colocados no mercado. Verifica-se que esta responsabilidade é, sobretudo, ditada pela necessidade de salvaguardar a saúde e segurança dos consumidores e pela responsabilização dos empresários que retiram vantagens da comercialização dos seus produtos pelos danos que esses produtos, quando defeituosos, causem. Cuida-se, também, de determinar em que medida o concurso do consumidor para os danos causados pelo produto pode excluir ou reduzir a responsabilidade do empresário produtor.
Corrosion is the primary failure mechanism for sea-based structures, as it plays an important rol... more Corrosion is the primary failure mechanism for sea-based structures, as it plays an important role in material degradation and structural integrity. The localized corrosion behavior is affected by the micromechanics and the electrochemistry of the material; however, there are very limited studies where both mechanisms are studied jointly, let alone relative to microstructural attributes, i.e., at the mesoscale. High-resolution strain maps are created on pre-loaded AA7050 in the transverse-short orientation via digital image correlation to identify strain accumulation with respect to the microstructure. Afterward, this material is subjected to a galvanic corrosion environment. In order to investigate the driving force for localized corrosion, the microstructure, the cathodic particles, the localized strain, and the evolution of surface topology caused by corrosion pitting are spatially characterized in the region of interest. The evolution of the corroded surface is tracked every 24 ...
A deformation mechanism map for a Ni-based superalloy is presented during cyclic loading at low (... more A deformation mechanism map for a Ni-based superalloy is presented during cyclic loading at low (300°C), intermediate (550°C), and high (700°C) temperatures for low (0.7%) and high (1.0%) applied strain amplitudes. Strain mapping is performed via digital image correlation (DIC) during interrupted fatigue experiments at elevated temperatures at 1, 10, 100 and 1000 cycles, for each specified loading and temperature condition. The DIC measurements are performed in a scanning electron microscope, which allows high-resolution measurements of heterogeneous slip events and a vacuum environment to ensure stability of the speckle pattern for DIC at high temperatures. The cumulative fatigue experiments show that the slip bands are present in the first cycle and intensify with number of cycles; resulting in highly localized strain accumulation. The strain mapping results are combined with microstructure characterization via electron backscatter diffraction. The combination of crystal orientations and high-resolution strain measurements was used to determine the active slip planes. At low temperatures, slip bands follow the {111} octahedral planes. However, as temperature increases, both the {111} octahedral and {100} cubic slip planes accommodate strain. The activation of cubic slip via cross-slip within the ordered intermetallic γ' phase has been well documented in Ni-based superalloys and is generally accepted as the mechanism responsible for the anomalous yield phenomenon. The results in this paper represent an important quantifiable study of cubic slip system activity at the mesoscale in polycrystalline γ-γ' Ni-based superalloys, which is a key advancement to calibrate the thermal activation components of polycrystalline deformation models.
Pregabalin is a medication that can decrease neuronal hyperexcitability, relieve neuropathic pain... more Pregabalin is a medication that can decrease neuronal hyperexcitability, relieve neuropathic pain, and reach stable plasma levels after a titration period of only a few days.Its use during oxaliplatin infusions was not able to decrease the incidence of chronic, oxalipaltin-related neuropathic pain, compared with placebo. Patients with colorectal cancer (CRC) receiving oxaliplatin (OXA) develop acute and chronic painful oxaliplatin-induced peripheral neuropathy (OXAIPN). Acute and chronic OXA-related neuropathies have different pathophysiological bases, but both lead to a common phenomenon: central sensitization (CS) of nociceptive neuronal networks, leading to increased sensitivity (hyperlgesia, allodynia) in the somatosensory system, the common ground of chronic neuropathic pain. Because CS is related to increased risk of painful OXAIPN, we hypothesized that preemptive use of the anti-hyperalgesic drug pregabaline (known to decrease CS) during OXA infusions would decrease the incid...
Microstructure attributes are responsible for heterogeneous deformation and strain localization. ... more Microstructure attributes are responsible for heterogeneous deformation and strain localization. In this study, the relation between residual strain fields and microstructure is examined and assessed by means of experiments and crystal plasticity modeling. The microstructure of rolled aluminum alloys (AA) in the 7050-T7451 condition was experimentally obtained with electron backscatter diffraction (EBSD) analysis along the rolling direction (L-T orientation), across the rolling direction (T-L orientation), and transverse to the rolling direction (T-S orientation). Each of these sections was also patterned using a novel microstamping procedure, to allow for strain mapping by digital image correlation (DIC). The measured microstructures were in turn used as input of an elasto-viscoplastic crystal plasticity formulation based on fast Fourier transforms (EVP-FFT). Comparisons between the strain maps obtained experimentally by the concurrent DIC-EBSD method and the EVP-FFT simulations were made for the three sections, corresponding to the initial textures. The comparisons showed that the predicted levels of strain concentration were reasonable for all three specimens from a statistical perspective, which is important to properly describe and predict the strains within an ensemble of components; however the spatial match with the actual strain fields needs improvement.
Este estudo centra-se na análise de um único diploma legal, o que versa, em Portugal, a responsab... more Este estudo centra-se na análise de um único diploma legal, o que versa, em Portugal, a responsabilidade do produtor e do distribuidor por produtos defeituosos colocados no mercado. Verifica-se que esta responsabilidade é, sobretudo, ditada pela necessidade de salvaguardar a saúde e segurança dos consumidores e pela responsabilização dos empresários que retiram vantagens da comercialização dos seus produtos pelos danos que esses produtos, quando defeituosos, causem. Cuida-se, também, de determinar em que medida o concurso do consumidor para os danos causados pelo produto pode excluir ou reduzir a responsabilidade do empresário produtor.
Corrosion is the primary failure mechanism for sea-based structures, as it plays an important rol... more Corrosion is the primary failure mechanism for sea-based structures, as it plays an important role in material degradation and structural integrity. The localized corrosion behavior is affected by the micromechanics and the electrochemistry of the material; however, there are very limited studies where both mechanisms are studied jointly, let alone relative to microstructural attributes, i.e., at the mesoscale. High-resolution strain maps are created on pre-loaded AA7050 in the transverse-short orientation via digital image correlation to identify strain accumulation with respect to the microstructure. Afterward, this material is subjected to a galvanic corrosion environment. In order to investigate the driving force for localized corrosion, the microstructure, the cathodic particles, the localized strain, and the evolution of surface topology caused by corrosion pitting are spatially characterized in the region of interest. The evolution of the corroded surface is tracked every 24 ...
A deformation mechanism map for a Ni-based superalloy is presented during cyclic loading at low (... more A deformation mechanism map for a Ni-based superalloy is presented during cyclic loading at low (300°C), intermediate (550°C), and high (700°C) temperatures for low (0.7%) and high (1.0%) applied strain amplitudes. Strain mapping is performed via digital image correlation (DIC) during interrupted fatigue experiments at elevated temperatures at 1, 10, 100 and 1000 cycles, for each specified loading and temperature condition. The DIC measurements are performed in a scanning electron microscope, which allows high-resolution measurements of heterogeneous slip events and a vacuum environment to ensure stability of the speckle pattern for DIC at high temperatures. The cumulative fatigue experiments show that the slip bands are present in the first cycle and intensify with number of cycles; resulting in highly localized strain accumulation. The strain mapping results are combined with microstructure characterization via electron backscatter diffraction. The combination of crystal orientations and high-resolution strain measurements was used to determine the active slip planes. At low temperatures, slip bands follow the {111} octahedral planes. However, as temperature increases, both the {111} octahedral and {100} cubic slip planes accommodate strain. The activation of cubic slip via cross-slip within the ordered intermetallic γ' phase has been well documented in Ni-based superalloys and is generally accepted as the mechanism responsible for the anomalous yield phenomenon. The results in this paper represent an important quantifiable study of cubic slip system activity at the mesoscale in polycrystalline γ-γ' Ni-based superalloys, which is a key advancement to calibrate the thermal activation components of polycrystalline deformation models.
Pregabalin is a medication that can decrease neuronal hyperexcitability, relieve neuropathic pain... more Pregabalin is a medication that can decrease neuronal hyperexcitability, relieve neuropathic pain, and reach stable plasma levels after a titration period of only a few days.Its use during oxaliplatin infusions was not able to decrease the incidence of chronic, oxalipaltin-related neuropathic pain, compared with placebo. Patients with colorectal cancer (CRC) receiving oxaliplatin (OXA) develop acute and chronic painful oxaliplatin-induced peripheral neuropathy (OXAIPN). Acute and chronic OXA-related neuropathies have different pathophysiological bases, but both lead to a common phenomenon: central sensitization (CS) of nociceptive neuronal networks, leading to increased sensitivity (hyperlgesia, allodynia) in the somatosensory system, the common ground of chronic neuropathic pain. Because CS is related to increased risk of painful OXAIPN, we hypothesized that preemptive use of the anti-hyperalgesic drug pregabaline (known to decrease CS) during OXA infusions would decrease the incid...
Microstructure attributes are responsible for heterogeneous deformation and strain localization. ... more Microstructure attributes are responsible for heterogeneous deformation and strain localization. In this study, the relation between residual strain fields and microstructure is examined and assessed by means of experiments and crystal plasticity modeling. The microstructure of rolled aluminum alloys (AA) in the 7050-T7451 condition was experimentally obtained with electron backscatter diffraction (EBSD) analysis along the rolling direction (L-T orientation), across the rolling direction (T-L orientation), and transverse to the rolling direction (T-S orientation). Each of these sections was also patterned using a novel microstamping procedure, to allow for strain mapping by digital image correlation (DIC). The measured microstructures were in turn used as input of an elasto-viscoplastic crystal plasticity formulation based on fast Fourier transforms (EVP-FFT). Comparisons between the strain maps obtained experimentally by the concurrent DIC-EBSD method and the EVP-FFT simulations were made for the three sections, corresponding to the initial textures. The comparisons showed that the predicted levels of strain concentration were reasonable for all three specimens from a statistical perspective, which is important to properly describe and predict the strains within an ensemble of components; however the spatial match with the actual strain fields needs improvement.
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Papers by alberto mello