Search Results - "Carvalho,João P. F."

Publication Catalog - "Carvalho,João P. F."

Refine Results
  1. 1

    Hydrogel bioinks of alginate and curcumin-loaded cellulose ester-based particles for the biofabrication of drug-releasing living tissue analogs

    Publication
    by Carvalho, João P. F.
    Other Authors: Teixeira, Maria C.; Lameirinhas, Nicole S.; Matos, Filipe S.; Luís, Jorge L.; Pires, Liliana et al.
    3D bioprinting is a versatile technique that allows the fabrication of living tissue analogs through the layer-by-layer deposition of cell-laden biomaterials, viz. bioinks. In this work, composite alginate hydrogel-based bioinks reinforced with curcumin-loaded particles of cellulose esters (CEpCUR) and laden with human keratinocytes (HaCaT) are developed. The addition of the CEpCUR particles, with sizes of 740 ± 147 nm, improves the rheological properties of the inks, increasing their shear stress and viscosity, while preserving the recovery rate and the mechanical and viscoelastic properties of the resulting fully cross-linked hydrogels. Moreover, the presence of these particles reduces the degradation rate of the hydrogels from 26.3 ± 0.8% (ALG) to 18.7 ± 1.3% (ALG:CEpCUR_10%) after 3 days in the culture medium. The 3D structures printed with the ALG:CEpCUR inks reveal increased printing definition and the ability to release curcumin (with nearly 70% of cumulative release after 24 h in PBS). After being laden with HaCaT cells (1.2 × 106 cells mL-1), the ALG:CEpCUR bioinks can be successfully 3D bioprinted, and the obtained living constructs show good dimensional stability and high cell viabilities at 7 days post-bioprinting (nearly 90%), confirming their great potential for application in fields like wound healing.
    2023 article Portugal open access
  2. 2

    Active packaging

    Publication
    by Carvalho, João P. F.
    Other Authors: Freire, Carmen S. R.; Vilela, Carla
    The inevitable augment of food demand, due to the growing world population, is contributing to the expansion of the global market of packaging materials. Thus, the active packaging concept emerges as an instrument to boost the safety, quality, and shelf-life of the packaged foods. In this context, the present chapter will provide a review on the latest advances in active agents for active food packaging. Focus will be set on active functions, such as antimicrobial and antioxidant activities, carbon dioxide emitting, and oxygen and ethylene scavenging, with emphasis on packaging materials derived from renewable resources as part of the widespread concern for sustainability. A strenuous effort will be made to outline representative studies published in the past years that have driven research on active agents for food packaging toward sustainable market solutions.
    2021 book part Portugal restricted access
  3. 3

    Aplicação de dados geofísicos na caracterização de falhas com potencial sismogénico no Vale Inferior do Tejo

    Publication
    by Carvalho, João P. F.
    Other Authors: Pinto, Carlos C.; Costa, Manuela; Rabeh, Taha; Terrinha, Pedro; Duarte, Henrique et al.
    O Vale Inferior do Tejo (VIT) tem sofrido os efeitos de sismos históricos. Algumas das fontes sismogénicas são conhecidas. Com vista a uma avaliação correcta das fontes sismogénicas em futuros estudos de perigosidade sísmica, integraram-se dados de reflexão sísmica, com dados de métodos potenciais e dados de epicentros relocalizados. As informações recolhidas a partir dos parâmetros das falhas irão ajudar à localização de fontes de sismos históricos utilizando elementos finitos de simulação de movimentos fortes.
    2010 conference output Portugal open access
  4. 4

    Looking for earthquake sources in the Lisbon area

    Publication
    by Carvalho, João P. F.
    Other Authors: Pinto, Carlos C.; Costa, M.; Rabeh, Taha
    The Lisbon and surrounding areas have suffered the effect of historical earthquakes that caused important damages and loss of lives. Some of these earthquake sources are local but they are still poorly known. The knowledge of these sources is important for seismic hazard studies. The use of geophysical methods in the area is required due to the difficulty in finding geological outcrops, together with low-slip rates and erosion/sedimentation processes that erase surface ruptures. Furthermore, most of earthquake occurs at great depth, emphasizing the need for the application of the latter methods. In this paper we present a revised structural interpretation of the area using newly reprocessed and reinterpreted seismic reflection and potential-field data, relocated epicentres, geological outcrop and well data. This interpretation differs in some aspects from previous ones. Well known active faults zones like the Azambuja fault and the Pinhal Novo-Setúbal fault have new interpretations, while other previously unknown structures, like the Ota-V. F. de Xira-Lisbon-Sesimbra fault zone, for example, have been interpreted. These studies, together with shallow geophysical data, which has been and will be acquired over selected targets from this work, will constitute na improvement to the seismic hazard evaluation of the area.
    2007 conference output Portugal open access
  5. 5

    Assessing the degree of fracturing and weathered layer thickness using seismic and GPR data

    Publication
    by Carvalho, João P. F.
    Other Authors: Pinto, Carlos C.; Lisboa, Jose; Sardinha, Rui; Catrapona, Afonso; Borges, José Fernando et al.
    2010 conference output Portugal open access
  6. 6

    Improving the seismic hazard evaluation of the Lisbon and Lower Tagus Valley area

    Publication
    by Carvalho, João P. F.
    Other Authors: Pinto, Carlos C.; Costa, M.; Heleno, S.; Silva, M.; Rabeh, Taha et al.
    The Lisbon and surrounding area of the Lower Tagus Valley has experienced in the past the effects of several moderate sized earthquakes that caused significant damage and destruction. They have been attributed to local sources, though in some cases the source remains to be located. The lack of outcrops in the flat lying Quaternary terrains, the low slip-rates of the area in connection with sedimentation and erosion rates that erase surface ruptures are among the causes of a poor association between faults and seismicty, which has opened way to geophysical studies. Seismic, potential-field and seismicity data have been recently used to improve the seismic hazard evaluation of the area. In this work we complement these studies with DTM and PSInSAR data with the purpose of obtaining an accurate evaluation of the seismic hazard of the study area. The correlation of improved epicentre locations with major fault zones located from the above mentioned data shows that we have progressed in the understanding of the earthquake sources in the region. Some structures show no apparent relationship with present-day seismicity but some are known to be active into the Quaternary. Further geophysical and geological studies are required to understand the causes.
    2008 conference output Portugal open access
  7. 7

    A soil classification for seismic hazard assessment and mitigation of the Algarve

    Publication
    by Carvalho, João P. F.
    Other Authors: Dias, Ruben Pereira; Pinto, Carlos C.; Leote, Jaime; Victor, L. Mendes
    The Algarve province of Portugal is located near the E-W Eurasia-Africa plate boundary. It is characterized by a moderate seismicity, with some important historical earthquakes causing important damage and economical losses. Not only has it suffered the effects of large plate boundary events but also the impact of local onshore moderate-sized earthquake sources. The seismic hazard evaluation and mitigation of the area is therefore of great importance to the local populations and the large number of tourists that frequent the region. This paper focuses the evaluation of the most interesting and useful geotechnical near-surface parameters and a soil classification. The classification based upon the European Code 8 for civil engineering and SPT bedrock data, was carried out for land use planning and design of critical facilities. P-wave and S-wave seismic velocities were obtained through the acquisition, processing and interpretation refraction profiles. Hundreds of SPT parameters from available boreholes drilled for engineering and water supply were used and subsoil classification based on geophysical and geotechnical parameters is presented. Other parameters, such as Vp/Vs ratios and the Poisson coefficient were estimated and were computed to provide information for future site effect studies. The experimental procedure tested here is relatively fast, economical and easy to perform and can be useful to estimate soil microzoning and seismic hazard mapping in the absence of local earthquake records.
    2008 conference output Portugal open access
  8. 8

    Characterization of a concealed fault zone using P and S-wave seismic reflection data

    Publication
    by Carvalho, João P. F.
    Other Authors: Ghose, R.; Pinto, Carlos C.; Borges, José Fernando
    2009 conference output Portugal open access
  9. 9

    Quality control and productivity in oak timber - from forest to the primary processing

    Publication
    by Carvalho, João P. F.
    Other Authors: Santos, José António dos; Santos, Joana
    Oak timber is valuated for its beauty, good mechanical properties and natural durability and may have multiple uses. An understanding of the factors that affect oak timber quality is essential. It is important to have quality control of physical, mechanical and technological wood characteristics in order to define the better primary processing and end-use. Silviculture may significantly impact wood quality and final stand value. Specific prescriptions will depend on species, site conditions, desired end product and management options. An appropriate silviculture with optimized technological operations allows a well use of wood even with small diameters. Adequate wood classification is required in order to optimize industrial processes and improve product quality. Quality criteria and procedures for round and sawtimber are referenced.
    2009 conference output Portugal open access
  10. 10

    Curvas de Classes de Qualidade da Estação para Povoamentos de Carvalho-Negral (Quercus pyrenaica) Willd.

    Publication
    by Carvalho,João P. F.
    Origin: SciELO Portugal
    Neste trabalho estabelecem-se curvas de classe de qualidade da estação para povoamentos de Carvalho-negral (Quercus pyrenaica Willd.) a partir de um modelo de crescimento em altura dominante desenvolvido para a espécie. Segue-se o método das equações algebricamente às diferenças com todos os possíveis intervalos de crescimento. São definidas 5 classes de qualidade, a variar entre os 7,0 e 22,0 m de altura à idade de referência de 50 anos, constatando-se a existência de uma ampla variação do índice de qualidade. Fornece-se uma forma para a estimação da idade total das árvores dominantes a partir da idade ao nível do diâmetro, e verifica-se que o número de anos necessários para atingir esse nível é independente da qualidade da estação.
    2006 article Portugal open access