4,086 research outputs found

    Topological defects in lattice models and affine Temperley-Lieb algebra

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    This paper is the first in a series where we attempt to define defects in critical lattice models that give rise to conformal field theory topological defects in the continuum limit. We focus mostly on models based on the Temperley-Lieb algebra, with future applications to restricted solid-on-solid (also called anyonic chains) models, as well as non-unitary models like percolation or self-avoiding walks. Our approach is essentially algebraic and focusses on the defects from two points of view: the "crossed channel" where the defect is seen as an operator acting on the Hilbert space of the models, and the "direct channel" where it corresponds to a modification of the basic Hamiltonian with some sort of impurity. Algebraic characterizations and constructions are proposed in both points of view. In the crossed channel, this leads us to new results about the center of the affine Temperley-Lieb algebra; in particular we find there a special subalgebra with non-negative integer structure constants that are interpreted as fusion rules of defects. In the direct channel, meanwhile, this leads to the introduction of fusion products and fusion quotients, with interesting mathematical properties that allow to describe representations content of the lattice model with a defect, and to describe its spectrum.Comment: 41

    MENÇÕES SOBRE O ESTADO NUTRICIONAL. Nos Registos Clínicos de Doentes Hospitalizadosvo

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    Está descrito que a frequência de desnutrição associada à doença (DAD) afecta cerca de 30 a 60% dos doentes no momento da admissão hospitalar e cerca de 10% dos indivíduos na comunidade. A DAD tem vindo a ser associada a graves consequências, como ao maior risco de infecções e de disfunção de órgãos e a um aumento significativo, não só da morbilidade e mortalidade, como da frequência e dos custos com os cuidados de saúde. A falta do reconhecimento e da monitorização dos aspectos relacionados com o estado nutricional, têm sido apontados como factores que contribuem para o aumento da frequência de DAD, durante o internamento hospitalar. Foi objectivo deste estudo avaliar a relevância que é dada a aspectos relacionados com o estado nutricional dos doentes (peso, ingestão alimentar) e saber se os doentes em risco nutricional ou desnutridos serão alvo de maior atenção por parte dos profissionais de saúde. Foi recolhida uma amostra sistemática de seis hospitais portugueses, correspondente a 42-50% do total de camas de cada serviço de internamento. Foram critérios de exclusão a doença crítica, a gravidez, a idade inferior a 18 anos, a incapacidade de aplicação do protocolo de rastreio nutricional e o tempo de internamento inferior a 24h. Recolheram- se dados sócio-demográficos, antropométricos, sobre as menções dos processos clínicos respeitantes ao peso, cuidados alimentares/nutricionais prestados e ingestão alimentar/nutricional dos doentes e aplicou-se uma ferramenta de rastreio nutricional (Nutritional Risk Screening 2002). Em 1152 doentes estudados, a frequência de risco nutricional variou entre os 28,5% e 47,3%, enquanto que a frequência de desnutrição antropométrica oscilou entre 6,3% e 14,9%. Dois em cada três doentes tinha menções acerca de cuidados alimentares/ nutricionais prestados nos processos clínicos, mas apenas um em cada três tinha o seu peso medido e registado. Os doentes desnutridos foram pesados com menor frequência mas a sua alimentação e problemas a ela associados foram monitorizados com maior regularidade. A frequência de DAD, no momento de admissão hospitalar, é muito elevada, enquanto que a de menções relevantes para o estado nutricional é muito escassa. A presente investigação reforça a necessidade de investir na sensibilização dos profissionais de saúde, sobre a importância do rastreio e da prescrição/monitorização da alimentação e do peso dos doentes, na admissão e durante todo o internamento hospitalar

    Development of permeable reactive biobarrier for the removal of PAHs by Trichoderma longibrachiatum

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    In this work, the formation of permeable reactive biobarriers (PRBBs) using Trichoderma longibrachiatum over nylon sponge as bioreactive medium for removal of polycyclic aromatic hydrocarbons (PAHs) was studied. Colony formation was pretested without PAH presence by inoculation of fungus into nylon sponge. The fungus formed a large quantity of strongly adhesive biofilm among nylon sponge. Afterwards, the ability of the developed bioreactive medium was tested to remediate phenanthrene in aqueous medium and in soil. In aqueous medium, a 90% of phenanthrene concentration reduction was observed after 14 d. However, the pollutant removal in soil requires previous fungus colonization and the attained level was around 70% after 28 d. Subsequently, the formed bioreactive material was used in a glass column reactor to evaluate its application as PRBBs. Mixtures of phenanthrene, benzo[a]anthracene and pyrene at several concentrations, from 100 to 400 μM, were treated. In all cases, the performance of the PRBB was satisfactory and total PAH removals were achieved. These results suggest that PRBBs of T. longibrachiatum supported on nylon sponge can be an effective method for the treatment of PAHs.This research was funded by Spanish Ministry of Science and Innovation and FEDER Funds (Project CTM 2011-25389) and for financial support of Marta Pazos under the Ramon y Cajal programme and Marta Cobas under the final project master grant "Campus do Mar Knowledge in depth"

    Parasite diversity in Oxydoras niger (Osteichthyes: Doradidae) from the basin of Solimões River, Amazonas state, Brazil, and the relationship between monogenoidean and condition factor.

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    This study describes the parasitic fauna of Oxydoras niger from the Coari Lake, tributary of the medium Solimões River, State of Amazonas, Brazil, and the relationship between the number of Monogenoidea and the condition factor. From a total of 27 examined fish, 70.3% were parasitised by at least one parasite species as follows: Ichthyophthirius multifiliis (Protozoa), Chilodonella sp. (Protozoa), Cosmetocleithrum gussevi, C. confusus, C. parvum and Cosmetocleithrum sp. (Monogenoidea), Paracavisona impudica (Acanthocephala), Cucullanus grandistomis (Nematoda), Proteocephalus kuyukuyu (Cestoda) and Dadaytrema sp. (Digenea). Monogenoidea helminthes were the most prevalent parasite when compared to protozoan and intestinal helminthes. This study showed that O. niger has a great parasite diversity composed mainly of monogenoideans followed by acanthocephalan and digenean. This is the first record of Dadaytrema in O. niger from the Brazilian Amazon. There was a positive correlation between the number of monogenoideans and the condition factor (Kn) of fish, and with this mean intensity of infection, fish welfare was not affected

    Advanced oxidation of organic matter in natural waters with TiO2 immobilized films

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    The purpose of this paper is to report the development of a laboratory -scale pilot based on the use of TiO2 photocatalytic thin films for degrading organic matter and pollutants from natural water. The photoreactor consists of a channel inclined with a glass plate coated by TiO2 in both faces and fixed at 1 cm from the bottom. The thin film was immobilized on the glass plates by Sputtering technique. The reactor was designed to be able of reproduce the hydraulic conditions of a water treatment plant. In experimental testing of degradation of organic matter with solar irradiation maximum efficiency of 50% was achieved. At optimal conditions it was possible to exceed the efficiencies of a full scale preozonization in a water treatment plant , thus providing a more sustainable process

    Study of pressure sensors placement using an Abdominal Aortic Aneurysm (AAA) model

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    An Abdominal Aortic Aneurysm (AAA) model for post-EVAR (endovascular aneurysm repair) analysis, including the blood flow, the bifurcated stent-graft, the aorta aneurysm wall motion and the stagnant blood inside the aneurysm sac, was built and solved using a Fluid Structure Interaction (FSI) code. The post-EVAR analysis aims to check the feasibility of EVAR surveillance using a remote pressure sensor, and the study of the pressure variations inside the aneurysm sac to determine the best placement position for the pressure sensor(s). First results suggest that aneurysm sac pressure measurement is feasible and can be a good indicator of aneurysms post-EVAR evolution.This work is supported by FCT under the project MIT-Pt/EDAM-EMD/0007/2008

    Dynamic collision avoidance system for a manipulator based on RGB-D data

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    The new paradigms of Industry 4.0 demand the collabora- tion between robot and humans. They could help and collaborate each other without any additional safety unlike other manipulators. The robot should have the ability of acquire the environment and plan (or re-plan) on-the- y the movement avoiding the obstacles and people. This paper proposes a system that acquires the environment space, based on a kinect sensor, performs the path planning of a UR5 manipulator for pick and place tasks while avoiding the objects, based on the point cloud from kinect. Results allow to validate the proposed system.Project ”TEC4Growth - Pervasive Intelligence, Enhancers and Proofs of Concept with Industrial Impact/NORTE-01-0145-FEDER-000020” is financed by the North Portugal Regional Operational. Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF). This work is also financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation -COMPETE 2020 Programme within project POCI-01-0145-FEDER-006961, and by National Funds through the FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) as part of project UID/EEA/50014/2013.info:eu-repo/semantics/publishedVersio

    Métodos para coleta de parasitos de peixes

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    Insensibilização dos peixes; Dados biométricos; Sequência de procedimentos para coleta de parasitos de peixe; Detecção e métodos de fixação de parasitos de peixes; Preparação dos reagentes fixadores de parasitos;bitstream/item/46620/1/AP-2011-Metodos-coleta-Circular.pd
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