Paulo Laranjeira - Academia.edu (original) (raw)
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Papers by Paulo Laranjeira
Cureus, 2021
Scurvy is a disease caused by vitamin C deficiency, historically associated with long sea voyages... more Scurvy is a disease caused by vitamin C deficiency, historically associated with long sea voyages, periods of famine and war. Currently, it is often misdiagnosed and underreported, as physicians tend to consider it a disease of the past. We present the case of a 79-year-old female who was admitted to the Emergency Department complaining of pruritus. The patient lived alone and in poor hygiene conditions. Diet was scarce. One week before admission she was in contact with flea-ridden stray dogs. Sometime later she noted several fleas and multiple pruritic small papules, crusts, and excoriations on her torso, limbs, palms, soles, and scalp. Physical examination showed the patient to be pale, emaciated, and poorly groomed. Laboratory analysis showed microcytic anemia. Flea bites were treated with oral antihistamines and prednisolone. Follow-up one month later showed weight gain and partial resolution of skin lesions. However, multiple small ecchymosis on both lower and upper limbs, and ...
Defect and Diffusion Forum, 2006
In this work the application of delay differential equations to the modelling of mass transport i... more In this work the application of delay differential equations to the modelling of mass transport in porous media, where the convective transport of mass, is presented and discussed. The differences and advantages when compared with the Dispersion Model are highlighted. Using simplified models of the local structure of a porous media, in particular a network model made up by combining two different types of network elements, channels and chambers, the mass transport under transient conditions is described and related to the local geometrical characteristics. The delay differential equations system that describe the flow, arise from the combination of the mass balance equations for both the network elements, and after taking into account their flow characteristics. The solution is obtained using a time marching method, and the results show that the model is capable of describing the qualitative behaviour observed experimentally, allowing the analysis of the influence of the local geome...
Journal of Dispersion Science and Technology, 2008
Fluidinova, a recent start‐up high technology engineering company, has developed and is now comme... more Fluidinova, a recent start‐up high technology engineering company, has developed and is now commercializing a novel continuous industrial reactor NETmix for the manufacture of high added value products, such as nanomaterials, microemulsions, and pharmaceutical products. Through this technology, Fluidinova, in cooperation with Instituto de Engenharia Biomédica, has developed and patented the industrial process for the synthesis of a new high quality product consisting of hydroxyapatite nanoparticles with extremely high purity and crystallinity to be used as biocompatible nanomaterial for biomedical and pharmaceutical applications, to improve the quality of the already existing hydroxyapatite based medical devices, such as bone grafts, coated implants, and drug delivery systems.
AIChE Journal, 2009
NETmix V R is a new technology for static mixing based on a network of chambers connected by chan... more NETmix V R is a new technology for static mixing based on a network of chambers connected by channels. The NETmix V R model is the basis of a flow simulator coupled with chemical reaction used to characterize macro and micromixing in structured porous media. The chambers are modeled as perfectly mixing zones and the channels as plug flow perfect segregation zones. A segregation parameter is introduced as the ratio between the channels volume and the whole network volume. Different kinetics and reactants injection schemes can be implemented. Results show that the number of rows in the flow direction and the segregation parameter control both macro and micromixing, but the degree of micromixing is also controlled by the reactants injection scheme. The NETmix V R model enables the systematic study of micromixing and macromixing for different network structures and reaction schemes, enabling the design of network structures to ensure the desired yield and selectivity. V
AIChE Journal, 2010
... NETmix®, a new type of static mixer: Experimental characterization and model validation. Paul... more ... NETmix®, a new type of static mixer: Experimental characterization and model validation. Paulo E. Laranjeira 1 ,; António A. Martins 1 ,; Maria Isabel Nunes 2 ,; José Carlos B. Lopes 1 ,; Madalena M. Dias 1,*. Article first published online: 25 JUN 2010. DOI: 10.1002/aic.12316. ...
Cureus, 2021
Scurvy is a disease caused by vitamin C deficiency, historically associated with long sea voyages... more Scurvy is a disease caused by vitamin C deficiency, historically associated with long sea voyages, periods of famine and war. Currently, it is often misdiagnosed and underreported, as physicians tend to consider it a disease of the past. We present the case of a 79-year-old female who was admitted to the Emergency Department complaining of pruritus. The patient lived alone and in poor hygiene conditions. Diet was scarce. One week before admission she was in contact with flea-ridden stray dogs. Sometime later she noted several fleas and multiple pruritic small papules, crusts, and excoriations on her torso, limbs, palms, soles, and scalp. Physical examination showed the patient to be pale, emaciated, and poorly groomed. Laboratory analysis showed microcytic anemia. Flea bites were treated with oral antihistamines and prednisolone. Follow-up one month later showed weight gain and partial resolution of skin lesions. However, multiple small ecchymosis on both lower and upper limbs, and ...
Defect and Diffusion Forum, 2006
In this work the application of delay differential equations to the modelling of mass transport i... more In this work the application of delay differential equations to the modelling of mass transport in porous media, where the convective transport of mass, is presented and discussed. The differences and advantages when compared with the Dispersion Model are highlighted. Using simplified models of the local structure of a porous media, in particular a network model made up by combining two different types of network elements, channels and chambers, the mass transport under transient conditions is described and related to the local geometrical characteristics. The delay differential equations system that describe the flow, arise from the combination of the mass balance equations for both the network elements, and after taking into account their flow characteristics. The solution is obtained using a time marching method, and the results show that the model is capable of describing the qualitative behaviour observed experimentally, allowing the analysis of the influence of the local geome...
Journal of Dispersion Science and Technology, 2008
Fluidinova, a recent start‐up high technology engineering company, has developed and is now comme... more Fluidinova, a recent start‐up high technology engineering company, has developed and is now commercializing a novel continuous industrial reactor NETmix for the manufacture of high added value products, such as nanomaterials, microemulsions, and pharmaceutical products. Through this technology, Fluidinova, in cooperation with Instituto de Engenharia Biomédica, has developed and patented the industrial process for the synthesis of a new high quality product consisting of hydroxyapatite nanoparticles with extremely high purity and crystallinity to be used as biocompatible nanomaterial for biomedical and pharmaceutical applications, to improve the quality of the already existing hydroxyapatite based medical devices, such as bone grafts, coated implants, and drug delivery systems.
AIChE Journal, 2009
NETmix V R is a new technology for static mixing based on a network of chambers connected by chan... more NETmix V R is a new technology for static mixing based on a network of chambers connected by channels. The NETmix V R model is the basis of a flow simulator coupled with chemical reaction used to characterize macro and micromixing in structured porous media. The chambers are modeled as perfectly mixing zones and the channels as plug flow perfect segregation zones. A segregation parameter is introduced as the ratio between the channels volume and the whole network volume. Different kinetics and reactants injection schemes can be implemented. Results show that the number of rows in the flow direction and the segregation parameter control both macro and micromixing, but the degree of micromixing is also controlled by the reactants injection scheme. The NETmix V R model enables the systematic study of micromixing and macromixing for different network structures and reaction schemes, enabling the design of network structures to ensure the desired yield and selectivity. V
AIChE Journal, 2010
... NETmix®, a new type of static mixer: Experimental characterization and model validation. Paul... more ... NETmix®, a new type of static mixer: Experimental characterization and model validation. Paulo E. Laranjeira 1 ,; António A. Martins 1 ,; Maria Isabel Nunes 2 ,; José Carlos B. Lopes 1 ,; Madalena M. Dias 1,*. Article first published online: 25 JUN 2010. DOI: 10.1002/aic.12316. ...