Percorrer por autor "Monge, Nuno"
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- Adaptation of liquid crystal textures. a contribution to textile design and to the sustainability of the traditional Arraiolos tapestry industryPublication . Monge, Nuno; Areias, M.; Ribeiro, A.C.The textures of liquid crystals, observed in polarized microscopy, show in general an extraordinary beauty depending on the phase and surface conditions. In this work, we present some textures obtained with different phases of liquid crystals and we propose to manipulate this images in different ways to be used as a design tool to create new decorative motives for the textile industry and also for the Arraiolos tapestry. At the end of this work, we present the result obtained from the combination of liquid crystal textures with the art of a painter.
- Cellulose nanocrystals: mind the microgap in iridescent Cellulose Nanocrystal FilmsPublication . Fernandes, Susete N.; Almeida, Pedro L.; Monge, Nuno; Aguirre, Luis E.; Reis, Dennys; de Oliveira, Cristiano L. P.; Neto, António M. F.; Pieranski, Pawel; Godinho, Maria H.Solid films prepared from cellulose nanocrystals (CNCs) present remarkable optical properties: iridescence,[1] selective reflection of left circularly polarized (LCP) light, and transmission of right circularly polarized (RCP) light.[2] The same phenomenon has been observed in certain insect cuticles, for example in the Plusiotis batesi as well as in the Plusiotis optima, where only LCP light is selectively reflected by the cholesteric structure forming the outer exocuticle.[3] In cellulosic films, the adopted left-handed chiral structure is attributed to the self-assembly of nanorods from chiral cellulose.[4] The value of the wavelength of the reflected structure (λ) depends upon the pitch (P) and the average refraction index (n) of the material according to the de Vries expression:
- Cellulosic liquid crystals for films and fibersPublication . Canejo, J. P.; Monge, Nuno; Echeverria, C.; Fernandes, S. N.; Godinho, M. H.Cellulose, the most abundant natural polymer on earth, is used in numerous applications in our day-to-day life. However, the discovery that cellulose-based systems could lead to the formation of liquid crystalline phases only dates to the 1970s. Compared with all known applications of cellulose, the liquid crystalline behavior has been less considered. Associated with this are the low solubility of cellulose and the existence of a chiral nematic precursor solution and its processing under the action of a shear field, which is used to produce fibers and films. In this review, we first conduct a short review of the main features of cellulosic liquid crystalline phases including the main textures observed by polarizing optical microscopy and the cholesteric phase characteristics of thermotropic and lyotropic systems observed for cellulose and cellulose derivatives. Then, we focus on the rheological properties of liquid crystalline solutions and special attention is given to the formation of striations developed during shear and the formation of the band texture, which appears during the relaxation process. Among the different techniques used, special emphasis is given to the results obtained by coupling rheology with optical microscopy (Rheo-optics) and nuclear magnetic resonance (Rheo-NMR) techniques. Some examples described in the literature, related to the use of cellulose and cellulose derivatives liquid crystals to the production of structural color scaffolds, stimuli-responsive films and fibers, are addressed. In these systems, the initial cholesteric phase determines the unique properties exhibited by the films and the fibers produced from cellulosic liquid crystalline systems.
- Design, control, and testing of a multifunctional soft robotic GripperPublication . Correia, Ana; Charters De Azevedo, Tiago; Leite, Afonso; Campos, Francisco M.; Monge, Nuno; Rocha, André; Mendes, Mário J. G. C.This paper proposes a multifunctional soft robotic gripper for a Dobot robot to handle sensitive products. The gripper is based on pneumatic network (PneuNet) bending actuators. In this study, two different models of PneuNet actuators have been studied, designed, simulated, experimentally tested, and validated using two different techniques (3D printing and molding) and three different materials: FilaFlex 60A (3D-printed), Elastosil M4601, and Dragonskin Fast 10 silicones (with molds). A new soft gripper design for the Dobot robot is presented, and a new design/production approach with molds is proposed to obtain the gripper’s PneuNet multifunctional actuators. It also describes a new control approach that is used to control the PneuNet actuators and gripper function, using compressed air generated by a small compressor/air pump, a pressure sensor, a mini valve, etc., and executing on a low-cost controller board—Arduino UNO. This paper presents the main simulation and experimental results of this research study.
- A glance at antimicrobial strategies to prevent catheter-associated medical infectionsPublication . Ricardo, Susana I. C.; Anjos, Inês I. L.; Monge, Nuno; Faustino, Célia M. C.; Ribeiro, Isabel A. C.Urinary and intravascular catheters are two of the most used invasive medical devices; however, microbial colonization of catheter surfaces is responsible for most healthcare-associated infections (HAIs). Several antimicrobial-coated catheters are available, but recurrent antibiotic therapy can decrease their potential activity against resistant bacterial strains. The aim of this Review is to question the actual effectiveness of currently used (coated) catheters and describe the progress and promise of alternative antimicrobial coatings. Different strategies have been reviewed with the common goal of preventing biofilm formation on catheters, including release-based approaches using antibiotics, antiseptics, nitric oxide, 5-fluorouracil, and silver as well as contact-killing approaches employing quaternary ammonium compounds, chitosan, antimicrobial peptides, and enzymes. All of these strategies have given proof of antimicrobial efficacy by modifying the physiology of pathogens or disrupting their structural integrity. The aim for synergistic approaches using multitarget processes and the combination of both antifouling and bactericidal properties holds potential for the near future. Despite intensive research in biofilm preventive strategies, laboratorial studies still present some limitations since experimental conditions usually are not the same and also differ from biological conditions encountered when the catheter is inserted in the human body. Consequently, in most cases, the efficacy data obtained from in vitro studies is not properly reflected in the clinical setting. Thus, further well-designed clinical trials and additional cytotoxicity studies are needed to prove the efficacy and safety of the developed antimicrobial strategies in the prevention of biofilm formation at catheter surfaces.
- Medidas para poupança de água – abordagens concretas implementadas no ISEL através do projeto de sustentabilidade MySafeWaterPublication . Matos, Manuel; Monge, Nuno; Gonçalves Cavaco Mendes, Mário José; Sousa, Ana Catarina; Silva, Hugo; Costa, Alexandra; Barreiros, Ana MariaO Projeto MySafeWater pretendeu fomentar o uso eficiente da água através de ações concretas para uma melhor gestão dos recursos hídricos numa escola do Ensino Superior, prevenindo a produção de resíduos, diminuído a pegada ecológica. Tendo por base os objetivos, este projeto assentou em três grandes eixos de atuação que serão descritos em detalhe na comunicação a apresentar e resumidamente descritos de seguida.
- Mind the microgap in iridescent cellulose nanocrystal filmsPublication . Fernandes, Susete; Almeida, Pedro L.; Monge, Nuno; Aguirre, Luís E.; Reis, Dennys; Oliveira, Cristiano; Neto, António M. F.; Pieranski, Pawel; Godinho, Maria Helena
- MySafeFiller adaptador para o enchimento de garrafas de água impresso em 3DPublication . Monge, Nuno; Matos, M.; Sousa, Ana Catarina; Barreiros, Ana Maria; Gonçalves Cavaco Mendes, Mário José; Costa, Alexandra; Silva, HugoO MySafeFiller facilita o enchimento de todo o tipo garrafas de água reutilizáveis, com diferentes diâmetros de bocais e diferentes tamanhos, em qualquer torneira de abastecimento de água potável, bebedouro público ou dispensador de água, permite encher a garrafa inclinada sem esta encostar à torneira e sem verter água. Além disso, evita a contaminação do local de abastecimento pelo contacto com o bocal de uma garrafa, e do bocal da garrafa pelo contacto com o local de abastecimento, torneira de abastecimento de água potável, bebedouro público ou dispensador de água.
- Novel antibacterial agents: an emergent need to win the battle against infectionsPublication . Simões, Natércia G.; Bettencourt, Ana F.; Monge, Nuno; Ribeiro, Isabel A.C.Multiple strategies have been recommended for prevention and control of antibacterial resistance. Solutions will need to be found soon if we are not to run the serious risk of losing the ability to treat bacterial infections, especially the ones arising from multi-resistant strains. Deep knowledge of the resistance mechanisms followed by novel therapeutic drugs and vaccines are needed. A consolidated, multidisciplinary and regulated strategy is required by this challenge.
- O projeto MySafeWater no ISELPublication . Barreiros, Ana Maria; Silva, Hugo; Matos, Manuel; Gonçalves Cavaco Mendes, Mário José; Monge, Nuno; Sousa, Ana Catarina; Costa, AlexandraO projeto MySafeWater pretendeu promover os objetivos nacionais e europeus, em matéria de Ambiente, no que se refere essencialmente à promoção do “consumo da água da torneira como forma ambientalmente sustentável de consumo, prevenindo a produção de resíduos e diminuindo a pegada ecológica”, através da informação e da conscientização do papel dos cidadãos na promoção do desenvolvimento sustentável em aspetos como a qualidade da água para consumo humano, abrangendo a participação ativa do público e pela sensibilização ambiental e a participação passiva do público.