Numerical uncertainty and its implications

A scrutiny of the contributions of key mathematicians and scientists shows that there has been much controversy (throughout the development of mathematics and science) concerning the use of mathematics and the nature of mathematics too. In this work, we try to show that arithmetical operations of approximation lead to the existence of a numerical uncertainty, which is quantic, path dependent and also dependent on the number system used, with mathematical and physical implications. When we explore the algebraic equations for the fine structure constant, the conditions exposed in this work generate paradoxical physical conditions, where the solution to the paradox may be in the fact that the fine-structure constant is calculated through different ways in order to ob-tain the same value, but there is no relationship between the fundamental physical processes which underlie the calculations, since we are merely dealing with algebraic relations, despite the expressions having the same physi-cal dimensions.info:eu-repo/semantics/publishedVersio

Bearing capacity of spread foundations on rock masses according to EC7

O Eurocódigo 7 (EC7) define diretivas para o projeto de fundações superficiais assentes em maciços rochosos e apresenta o exemplo de um método para estimar a capacidade resistente presumida deste tipo de fundação. Contudo, o mesmo não tem em conta importantes fatores que influenciam a capacidade de carga da fundação, o que pode ser considerado como uma importante limitação. Neste trabalho, o método recomendado pelo EC7 é comparado com dois métodos existentes na literatura. São utilizados dois casos de estudo simples e os resultados são comparados. Da análise dos resultados detetou-se que a capacidade resistente obtida utilizando o método do EC7 é a menos conservativa num dos casos analisados e a mais conservativa, conjuntamente com um dos métodos alternativos, no outro caso estudado. Isto revela que o método preconizado pelo EC7 deve ser usado com precaução mesmo em casos muito simples.In Eurocode 7 (EC7), some guidelines are provided for the design of spread foundations built on rock masses and a method for the calculation of the bearing capacity for this type of foundations is suggested. However, this method does not take into account important factors that influence the bearing capacity of the foundation, which can be an important limitation of the method. In this work, the EC7 method is compared with two other methods that can be found in literature. They are applied to two simple examples and the results are compared. The results revealed the EC7 method as the least conservative in one of the analysed cases and the greatest conservative, jointly with other used method, in the other studied case. This means that the EC7 method should be used with caution even for very simple cases

Shacc: a functional prototyper for a component calculus

For individual study onlyOver the last decade component-based software development arose as a promising paradigm to deal with the ever increasing complexity in software design, evolution and reuse. Shacc is a prototyping tool for component-based systems in which components are modelled coinductively as generalized Mealy machines. The prototype is built as a Haskell library endowed with a graphical user interface developed in Swing.Fundação para a Ciência e a Tecnologia (FCT

Immunoscore and Microbiome in Colorectal Cancer: What’s New?

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy and the fourth leading cause of cancer death in the world, accounting for about 1.4 million new cases and almost 700,000 deaths in 2012. The clinical outcome and the tumor progression are now considered the result of a balance between the invasiveness of the tumor and the immune response of the patient against the tumor. The immune system has the ability to control and shape cancer through a mechanism called immunoediting, which include elimination, equilibrium, and escape. The consensus Immunoscore is a scoring system that outlines the density of CD3+ and CD8+ T-cell effectors existent in the tumor and its invasive margin. The pre-existing intra-tumoral immunity could be enhanced and activated by immunotherapy. Immunoscore could be a good prognostic marker, by identifying patients at high risk of tumor recurrence and stratifying patients who could benefit from adjuvant therapies. Human surfaces and cavities are populated by numerous microbial communities, and they play an indispensable role in human health, as they interact with the immune system. The authors made a literature revision concerning the role of Immunoscore and microbiome in colorectal cancer

Conjugated linoleic acid reduces permeability and fluidity of adipose plasma membranes from obese Zucker rats

NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. July 2010; 398 (2): 199-204.Conjugated linoleic acid (CLA) is a dietary fatty acid frequently used as a body fat reducing agent whose effects upon cell membranes and cellular function remain unknown. Obese Zucker rats were fed atherogenic diets containing saturated fats of vegetable or animal origin with or without 1% CLA, as a mixture of cis(c)9,trans(t)11 and t10,c12 isomers. Plasma membrane vesicles obtained from visceral adi- pose tissue were used to assess the effectiveness of dietary fat and CLA membrane incorporation and its outcome on fluidity and permeability to water and glycerol. A significant decrease in adipose membrane fluidity was correlated with the changes observed in permeability, which seem to be caused by the incor- poration of the t10,c12 CLA isomer into membrane phospholipids. These results indicate that CLA supple- mentation in obese Zucker rats fed saturated and cholesterol rich diets reduces the fluidity and permeability of adipose membranes, therefore not supporting CLA as a body fat reducing agent through membrane fluidification in obese fat consumers

Structural integrity of polymeric components produced by additive manufacturing (Am)—polymer applications

Funding Information: Authors acknowledge Funda??o para a Ci?ncia e a Tecnologia (FCT-MCTES) for its financial support via the project UIDB/00667/2020 (UNIDEMI) and project UIDB/00285/2020 (CEMMPRE). Funding Information: Funding: Authors acknowledge Fundação para a Ciência e a Tecnologia (FCT-MCTES) for its financial support via the project UIDB/00667/2020 (UNIDEMI) and project UIDB/00285/2020 (CEMMPRE). Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.In the work presented herein, the structural integrity of polymeric functional components made of Nylon-645 and Polylactic acid (PLA) produced by additive manufacturing (Fused Deposition Modelling, FDM) is studied. The PLA component under study was selected from the production line of a brewing company, and it was redesigned and analyzed using the Finite Element Method, 3D printed, and installed under real service. The results obtained indicated that, even though the durability of the 3D printed part was lower than the original, savings of about EUR 7000 a year could be achieved for the component studied. Moreover, it was shown that widespread use of AM with other specific PLA components could result in even more significant savings. Additionally, a metallic hanger (2700 kg/m3 ) from the cockpit of an airplane ATR 70 series 500 was successfully redesigned and additively manufactured in Nylon 645, resulting in a mass reduction of approximately 60% while maintaining its fit-for-purpose. Therefore, the components produced by FDM were used as fully functional components rather than prototype models, which is frequently stated as a major constraint of the FDM process.publishersversionpublishe

Influence of heat pipe operating temperature on exhaust heat thermoelectric generation

Increasingly stringent targets on energy efficiency and emissions, as well as growing vehicle electrification are making attractive the electric recovery of the energy normally wasted through the tailpipe of Internal Combustion Engines. Recent developments in thermoelectrics (TE) may soon make them a viable solution for such applications. This team has been exploring the potential of using TE modules in combination with variable conductance heat pipes for transferring the exhaust heat to the generator with very low thermal resistance and at a constant, prescribed temperature. This passive temperature control eliminates the need for by-pass systems in the event of temperature overshoots. The operating temperature of a generator should be as high as possible in order to maximize the Seebeck effect. However, currently available modules are temperature limited. Moreover, the higher the HP temperature the less the usable thermal power at the exhaust will be (heat can only be transferred to from a hotter to a colder body). The present work assesses both theoretically and experimentally the influence of the HP temperature in the electric output of a thermoelectric generator. A small diesel engine and a generator were tested and it was found that a high HP operating temperature is only limitative for performance in the cases where low exhaust temperature and low engine power are present. In those cases it is possible to estimate an optimal HP temperature in order to maximize power output. The combined use of Seebeck modules and heat pipes was found to be highly advantageous in various ways.Fundação para a Ciência e a Tecnologia (FCT), FEDER e POFC CompeteMIT Portugal EDAM, Project MOBI-MP

Control and operation of a three-phase local energy router for prosumers in a smart community

UID/EEA/00066/2019From the electrical energy point of view, the smart community (SC) concept is meant to be as a sustainable and environmentally friendly alternative to the classical configuration. The SC includes small-scale renewable energy sources (RES) and small-scale energy storage system (ESS). The SC energy management system acts as an aggregator, aiming to assure benefits for community stakeholders. These trends led to the energy routers (ERs) concept. This study proposes and describes the control strategies for these ERs to contribute to the SC goals. The approach of these strategies increases the RES adjustability, contributing to maintain the ESS state of health. The ER is able to operate simultaneously with active and reactive power control, besides compensating SC grid voltage imbalances, and providing ancillary services to the SC. The proposed control strategies are validated by simulations and experiments.publishersversionpublishe

Energy router for SC: GC, SA and transition mode controls

UID/EEA/00066/2019 Grant agreement no. 731155 - Storage4Grid project.From the electrical point of view, the concept of smart community (SC) was defined as a distributed system consisting of a set of smart homes, distributed energy resources (DERs) and energy storage systems (ESSs) using SC controllers to enable smart power management. In this context, the SC energy management system (SCEMS) acts as aggregator of these resources, aiming to assure benefits for every SC stakeholder by setting the SC operation. The references given by the SCEMS must be accurately tracked by the energy routers (ERs), intended as one of the key components of the SC, acting as smart interface between the utility grid and the prosumers' DER and ESS. This study proposes a flexible, robust and simple control strategy for a single-phase ER. The ER regulates the active and reactive powers in grid-connected (GC) mode, and the voltage and frequency when operating in stand-alone (SA) mode. A seamless transition between SA and GC is demonstrated, avoiding undesired transients. The design and implementation of the proposed control strategy is progressively explained. Finally, this is tested via simulation (in PSCAD/EMTDC software) and verified with the experimental prototype.publishersversionpublishe

Soil stabilisation using alkaline activation of fly ash for self-compacting rammed earth construction

This paper studies the effectiveness of alkaline activation of low-calcium fly ash on the improvement of residual granitic soils to be used on rammed-earth construction. Different liquid:solid ratios, alkali concentrations and Na2O : ash ratios were tested. Effect of calcium hidroxide, sodium chloride and concrete superplasticiser is also reported. Compressive strength up to 7 days at 60ºC was determined. Results show that, in terms of mechanical strength, there is an optimum value for the activator:solids ratio and the alkali concentration, and that a decrease in the Na2O:ash ratio results in strength increase. No improvement was observed with the sodium chloride or the superplasticiser, while the calcium produced only a short term increase in strength. SEM/EDS analysis were used to analyse microstructural development, showing that strength is fairly related to the Si:Al and Na:Si ratios