Structural schemes for one dimension stationary equations

In this paper, we propose a new paradigm for finite differences numerical methods, based on compact schemes to provide high order accurate approximations of a smooth solution. The method involves its derivatives approximations at the grid points and the construction of structural equations deriving from the kernels of a matrix that gathers the variables belonging to a small stencil. Numerical schemes involve combinations of physical equations and the structural relations. We have analysed the spectral resolution of the most common structural equations and performed numerical tests to address both the stability and accuracy issues for popular linear and non-linear problems. Several benchmarks are presented that ensure that the developed technology can cope with several problems that may involve non-linearity.S. Clain acknowledges the financial support by Portuguese Funds through Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/00324/2020. R. M. S. Pereira acknowledges the financial support by Portuguese Funds through Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020. P. A. Pereira acknowledges the financial support by Portuguese Funds through Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/00013/2020. Diogo Lopes acknowledges the financial support by national funds (PIDDAC), through the FCT – Fundação para a Ciência e a Tecnologia and FCT/MCTES under the scope of the projects UIDB/05549/2020 and UIDP/05549/2020. S. Clain and R. M.Pereira acknowledge the financial support by FEDER – Fundo Europeu de Desenvolvimento Regional, through COMPETE 2020 – Programa Operacional Fatores de Competitividade, and the National Funds through FCT, project N◦. POCI-01-0145-FEDER-028118

Materiais para o Fim do Mundo 3

Para estudar o imaginário do fim do mundo, o Instituto de Literatura Comparada Margarida Losa organiza, desde 2013, uma série de seminários abertos, coincidindo com os equinócios e os solstícios. Os libretos Materiais para o Fim do Mundo recolhem alguns ensaios apresentados nesses seminários, ou textos afins. Neste terceiro libreto, Isabel Cristina Rodrigues interroga o limite do testemunhável nas palavras de Marguerite Duras e nas imagens de Alain Resnais, em Hiroshima Mon Amour; Paulo Alexandre Pereira estuda o imaginário do apocalipse na poesia de Tomaz Kim, num século ferido pela guerra e pela wasteland; e Raquel S. lê Finisterra de Carlos de Oliveira e Beginning to End de Samuel Beckett, questionando os conceitos de mundo, de fim e da linguagem (im)possível depois do fim

A constitutive three-dimensional interface model for masonry walls subjected to high strain rates

Investigation of the dynamic properties of construction materials is critical for structural engineering. The strain rate effect influences the properties of most constructions materials and this effect on materials such as concrete or steel has been intensively investigated. However, such studies on masonry materials are scarce. Understanding the strain rate effect on masonry materials is important for proper modelling and design of masonry structures under high velocity impacts or blast loads. The work, described in this paper, aims to study the behaviour of masonry at different strain rates. First, a drop weight impact machine is used at different heights and weights introducing different levels of strain rate. Then, a dynamic constitutive material interface model that includes an non-associated flow rule and high strain rate effects is proposed. The model capability is validated with numerical simulations of unreinforced block work masonry walls subjected to impact.(undefined

A Signaling View into the Inflammatory Tumor Microenvironment

The development of tumors requires an initiator event, usually exposure to DNA damaging agents that cause genetic alterations such as gene mutations or chromosomal abnormalities, leading to deregulated cell proliferation. Although the mere stochastic accumulation of further mutations may cause tumor progression, it is now clear that an inflammatory microenvironment has a major tumor-promoting influence on initiated cells, in particular when a chronic inflammatory reaction already existed before the initiated tumor cell was formed. Moreover, inflammatory cells become mobilized in response to signals emanating from tumor cells. In both cases, the microenvironment provides signals that initiated tumor cells perceive by membrane receptors and transduce via downstream kinase cascades to modulate multiple cellular processes and respond with changes in cell gene expression, metabolism, and morphology. Cytokines, chemokines, and growth factors are examples of major signals secreted by immune cells, fibroblast, and endothelial cells and mediate an intricate cell-cell crosstalk in an inflammatory microenvironment, which contributes to increased cancer cell survival, phenotypic plasticity and adaptation to surrounding tissue conditions. Eventually, consequent changes in extracellular matrix stiffness and architecture, coupled with additional genetic alterations, further fortify the malignant progression of tumor cells, priming them for invasion and metastasis. Here, we provide an overview of the current knowledge on the composition of the inflammatory tumor microenvironment, with an emphasis on the major signals and signal-transducing events mediating different aspects of stromal cell-tumor cell communication that ultimately lead to malignant progression.The work in the authors’ laboratory was supported by Fundação para a Ciência e a Tecnologia (FCT), Portugal, through grant UID/MULTI/04046/2019 to Research Unit BioISI and fellowship SFRH/BD/109162/2015 to JFSP.info:eu-repo/semantics/publishedVersio

Desorption of cellulases from cotton powder

Cotton fabrics were treated with three different Trichoderma reesei cellulase preparations (total crude – TC, endoglucanase enriched – EG-rich, cellobiohydrolase enriched – CBH-rich) using mechanical agitation to produce cotton powder. Desorption of cellulase enzymes from the cotton powder was then performed by washing with buffer. After 3 washings most of the protein was desorbed from the cotton powder and the amount of sugars released in the latter washings was negligible. TC and CBH-rich preparations produced a finer cellulose powder than EGs. The desorption process caused a decrease in degree of polymerisation (DP) specially for the cotton treated with EGs and a marked increase in polydispersity (Pd ) for all preparations

Spatial and temporal variability of precipitation and drought in Portugal

The spatial variability of precipitation and drought are investigated for Portugal using monthly precipitation from 74 stations and minimum and maximum temperature from 27 stations, covering the common period of 1941–2006. Seasonal precipitation and the corresponding percentages in the year, as well as the precipitation concentration index (PCI), was computed for all 74 stations and then used as an input matrix for an R-mode principal component analysis to identify the precipitation patterns. The standardized precipitation index at 3 and 12 month time scales were computed for all stations, whereas the Palmer Drought Severity Index (PDSI) and the modified PDSI for Mediterranean conditions (MedPDSI) were computed for the stations with temperature data. The spatial patterns of drought over Portugal were identified by applying the S-mode principal component analysis coupled with varimax rotation to the drought indices matrices. The result revealed two distinct sub-regions in the country relative to both precipitation regimes and drought variability. The analysis of time variability of the PC scores of all drought indices allowed verifying that there is no linear trend indicating drought aggravation or decrease. In addition, the analysis shows that results for SPI-3, SPI-12, PDSI and MedPDSI are coherent among them

Sobre as Forças

[Extrato] Em dinâmica de sistemas mecânicos é por demais importante saber identificar os diversos tipos de forças que atuam nos corpos. De uma forma geral, pode definir-se força como sendo uma grandeza física que representa a medida quantitativa da interação dos corpos que constituem as máquinas e mecanismos. Como é sabido, em dinâmica de sistemas mecânicos, as forças tendem a modificar o estado de movimento (ou repouso) dos corpos materiais (...)

Sobre o carro analisado

Este documento contém uma análise descritiva do carro analisado no âmbito da unidade curricular Integradora II

Sobre o desempenho do carro

Este documento contém os procedimentos fundamentais para efetuar o desempenho do carro analisado no âmbito da unidade curricular Integradora II

Quasi-Topological Quantum Field Theories and Z2Z_2 Lattice Gauge Theories

We consider a two parameter family of $Z_2$ gauge theories on a lattice discretization $T(M)$ of a 3-manifold $M$ and its relation to topological field theories. Familiar models such as the spin-gauge model are curves on a parameter space $\Gamma$. We show that there is a region $\Gamma_0$ of $\Gamma$ where the partition function and the expectation value of the Wilson loop for a curve $\gamma$ can be exactly computed. Depending on the point of $\Gamma_0$, the model behaves as topological or quasi-topological. The partition function is, up to a scaling factor, a topological number of $M$. The Wilson loop on the other hand, does not depend on the topology of $\gamma$. However, for a subset of $\Gamma_0$, depends on the size of $\gamma$ and follows a discrete version of an area law. At the zero temperature limit, the spin-gauge model approaches the topological and the quasi-topological regions depending on the sign of the coupling constant.Comment: 19 pages, 13 figure