Micro-EDXRF, SEM-EDS and OM characterisation of tin soldering found in handle attachments of Roman situlae from Conimbriga (Portugal)

Tin (Sn) or a Sn-rich solder applied to copper-based artefacts has been frequently used at least, since the Ancient Greece, although scarce studies have been published concerning the technology of this metallurgical joining technique. Several filler remnants were reported to be found in a Roman collection of handle attachments of situlae or cauldrons (2nd century BCE–5th century CE) from the archaeological site of Conimbriga, a Roman city from the Lusitania Province (Portugal). All these artefacts were cast in high leaded coppers and bronzes. The present study aims to contribute to the knowledge of Sn-rich soldering, an ancientmetallurgical joining technique, by the characterisation of the fusible metallic alloy present in 10 Roman artefacts by means of micro-energy dispersive X-ray fluorescence spectrometry (micro-EDXRF), scanning electron microscopy with energy dispersive X-ray (SEM-EDS) microanalysis and optical microscope (OM) observations. Results of studied solders show the presence of Cu-Sn alloys, with Sn contents ranging from δ to η phase composition (30–60wt% Sn). As the attachments were made in leaded copper alloys, it was also observed, in some cases, the melting of the interdendritic Pb-rich chains with long-range diffusion of the solder alloy into the substrate. The fillers compositions suggest that the handle attachments have been joined to a situla body by the soldering metallurgical process with Sn or a Sn-rich alloy. The studied leaded Cu-Sn attachments, probably formulated by local craftsman, were joined into the body of a situla or cauldron with a soft solder (soldering), a common metallurgical joint from Antiquity, although no relation was found between composition or typology and the Sn or Sn-rich solder

Influence of technological progress and renewability on the sustainability of ecosystem engineers populations

Overpopulation and environmental degradation due to inadequate resource-use are outcomes of human's ecosystem engineering that has profoundly modified the world's landscape. Despite the age-old concern that unchecked population and economic growth may be unsustainable, the prospect of societal collapse remains contentious today. Contrasting with the usual approach to modeling human-nature interactions, which are based on the Lotka-Volterra predator-prey model with humans as the predators and nature as the prey, here we address this issue using a discrete-time population dynamics model of ecosystem engineers. The growth of the population of engineers is modeled by the Beverton-Holt equation with a density-dependent carrying capacity that is proportional to the number of usable habitats. These habitats (e.g., farms) are the products of the work of the individuals on the virgin habitats (e.g., native forests), hence the denomination engineers of ecosystems to those agents. The human-made habitats decay into degraded habitats, which eventually regenerate into virgin habitats. For slow regeneration resources, we find that the dynamics is dominated by cycles of prosperity and collapse, in which the population reaches vanishing small densities. However, increase of the efficiency of the engineers to explore the resources eliminates the dangerous cyclical patterns of feast and famine and leads to a stable equilibrium that balances population growth and resource availability. This finding supports the viewpoint of growth optimists that technological progress may avoid collapse

Numerical modeling and optimization of an air handling unit

Concerns about the efficiency of Heating, Ventilating, and Air Conditioning systems, including Air Handling Units (AHUs), started in the last century due to the energy crisis. Thenceforth, important improvements on the AHUs performance have emerged. Among the various improvements, the control of the AHUs and the redesign of the fans are the most important ones. Although, with increasingly demanding energy efficiency requirements, other constructive solutions must be investigated. Therefore, the objective of this work is to investigate, using a computational fluid dynamics (CFD) tool, the fluid flow inside an AHU and to analyze different constructive solutions in order to improve the AHU performance. The numerical model provided a reasonable agreement with the experimental results in terms of air flow rate, despite the assumed simplifications. Regarding the constructive solution concept, the CFD results for the two different flow control units (FCUs) showed improvements in terms of fan static pressure rise. Under real conditions, improvements of 15.1% when compared with the case without the FCU were obtained. Nevertheless, it was concluded that the axial component of the air velocity, at the fan exit, can have a determinant impact on the FCU viability. Finally, an improved FCU geometry, with a new body shape, which resulted in an additional improvement of 6.1% in the fan static pressure rise.The second author would like to express his gratitude for the support given by FCT through the Grant SFRH/BD/130588/2017

An innovative platform for territorial marketing and location benchmarking

When looking for locations to install their production or business units, entrepreneurs undertake a well established decision process that starts with the very first option to invest in a specific country and finishes with a final decision over a commonly named “short list”. In order to support investors looking for investment locations in Portugal across the decision process mentioned before, an internet platform was developed and deployed worldwide as a result of a development partnership between the University of Minho and Innovation Point S.A., a technological start-up. The platform, named where-to-invest-in-portugal.com and often classified as a territorial marketing & analysis platform, includes an extensive set of resources to support potential investors. Among them, the so-called Investor_DSS channel is a multicriteria Decision Support System intended to model the geographical screening and find the best ranked set of locations (municipalities) for a particular location exercise. Other channels include fact sheets and databases for Business Space Offers and Business Opportunities. A special channel is dedicated to the Mayors, a space where they may address an invitation for direct investment in their Municipalities. This paper describes the architecture of the platform and some of the relevant developments related to

An efficient adaptive data-link-layer architecture for LoRa networks

LoRa is one of the most popular low-power wireless network technologies for implementation of the Internet of Things, with the advantage of providing long-range communication, but lower data rates, when compared with technologies such as Zigbee or Bluetooth. LoRa is a single-channel physical layer technology on top of which LoRaWAN implements a more complex multi-channel network with enhanced functionalities, such as adaptive data rate. However, LoRaWAN relies on expensive hardware to support these functionalities. This paper proposes a LoRa data-link-layer architecture based on a multi-layer star network topology that adapts relevant LoRa parameters for each end node dynamically taking into account its link distance and quality in order to balance communication range and energy consumption. The developed solution is comprised of multiple components, including a LoRa parameter calculator to help the user to configure the network parameters, a contention-free MAC protocol to avoid collisions, and an adaptive spreading factor and transmission power mechanism. These components work together to ensure a more efficient use of the chosen ISM band and end node resources, but with low-cost implementation and operation requirements.This research was funded by FEDER through COMPETE2020—Programa Operacional Competitividade e Internacionalização (POCI) grant number POCI-01-0145-FEDER-028247 and by FCT—Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/202

Contact lens care solutions and ocular surface

Safe wear of non-daily disposable contact lenses require care systems to ensure disinfection and cleaning to allow the lens to be reused after a period of non lens wear (typically overnight). To do so, modern care systems, also known as multipurpose solutions (MPS) or multipurpose disinfecting solutions (MPDS) try to mimic the environment of the ocular surface regarding pH, osmolality, surface tension or viscosity while introducing other singular properties as a wide-spectrum antimicrobial activity and high cleaning performance. This delicate equilibrium or properties is challenging and sometimes results in adverse events that have drawn the attention of the CL industry and scientifi c community to these systems with an increased intensity during the past decade. Even with disposable lenses, safety is still a concern and presently we are in front of a new paradigm of solutions development, which must provide reinforced disinfecting capabilities and at the same time improve the compatibility with the ocular surface. Indeed, disinfection effi cacy against different new strains of microorganisms and compatibility with the ocular surface have been two aspects widely covered in the recent scientifi c literature, topics that will also be addressed in this chapter

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

Estudo da Sensibilização aos Aeroalergenos Phl p 1, Phl p 5, Ole e 1 e Ole e 2 em Doentes com Patologia Alérgica Sazonal

Estudo da Sensibilização aos Aeroalergenos Phl p 1, Phl p 5, Ole e 1 e Ole e 2 em Doentes com Patologia Alérgica Sazonal Cátia Coelho2, Elsa Caeiro2,4, Maria Luísa Lopes1, Ana Filipa Lopes3, Raquel Ferro2, José Eduardo Moreira3, Célia Antunes3,4, Rui Brandão4,5 1Hospital de Santa Luzia, Elvas, Portugal; 2Sociedade Portuguesa de Alergologia e Imunologia Clínica (SPAIC), Lisboa, Portugal; 3Departamento de Química, Universidade de Évora, Portugal; 4Instituto de Ciências Agrárias e Ambientais Mediterrânicas (ICAAM), Universidade de Évora, Portugal; 5 Departamento de Biologia, Universidade de Évora, Portugal Introdução: A sensibilização aos pólenes depende de vários factores nomeadamente do tipo de vegetação local e sabe-se que a sintomatologia não está apenas associada à exposição aos pólens mas também a partículas, algumas das quais resultantes da rotura dos grãos de pólen sendo posteriormente aerossolizadas. Objectivos: Relacionar a sensibilização de doentes com a concentração polínica atmosférica e a concentração de alguns dos respectivos aerolergenos. Métodos: Das consultas externas de Imunoalergologia dos hospitais de Évora e Elvas seleccionaram-se doentes que apresentavam queixas sazonais de rinite alérgica e asma brônquica, aos quais foram realizados testes cutâneos em Prick, standardizados, aos pólenes identificados na região. A 55 doentes foram realizados testes ao extracto de Phleum, aos seus alergénios Phl p 1 e Phl p 5, bem como aos extractos das restantes gramíneas e a 47 doentes foram realizados testes ao extracto de Olea, aos seus alergénios Ole e 1 e Ole e 2. Monitorizaram-se diariamente as partículas polínicas e os aeroalergenos mediante 2 colectores específicos para cada tipo. Resultados: A percentagem de doentes que é sensível aos 3 extractos de Phleum (Phleum total, Phl p 1 e Phl p 5) é de 51% , a dos que são sensíveis aos extractos de Phleum total e Phl p 1 é de 16 % e a dos que são sensíveis a Phleum total e Phl p5 é de 2%. A percentagem de doentes que é sensível a somente um dos extractos é de 20% e os que não têm qualquer sensibilidade são 11%. A percentagem de doentes que é sensível aos 3 extractos de Olea (Olea total, Ole e 1 e Ole e 2) é de 23%, a dos que são sensíveis à Olea total e Ole e 1 é de 21 % e a dos que são sensíveis à Olea total e Ole e 2 é de apenas 4%. A percentagem dos que são sensíveis a um dos extractos é de 19% e a dos que não apresentaram qualquer sensibilidade é de 32%. Conclusões: Podemos concluir que 89% dos doentes mostraram ser sensíveis aos alergénios da gramínea Phleum pratense pois mostraram positividade tanto ao extracto de Phleum e/ou aos seus alergénios Phl p 1 e Phl p 5. Em relação à oliveira, 44% dos doentes são alérgicos a este pólen pois são sensíveis ao seu alergénio major, Ole e 1. Em ambos os casos estão correlacionados com os aeroalergenos detectados nas amostras de ar, sendo a sensibilidade aos pólenes de gramíneas maior que a sensibilidade ao pólen de oliveira. Mais estudos devem ser realizados para despiste de reacções cruzadas nomeadamente quanto à Olea com outras plantas da região

Motivation in mechanics of materials classes: An experimental approach

Motivation in mechanics of materials classes: An experimental approachThis work presents a novel didactic methodology for the approximation of the students to the subject of Mechanics of Materials, with the aim of improving the understanding of the inertia moment, and its relevance on the mechanical behaviour of structures. The students have grouped on groups of two to three persons. The work consisted in designing the most efficient beam having in mind several design constraints. Tensile tests were performed to determine the relevant material properties. Those were used for the analytic dimensioning of the beams. The aim of the work is to obtain the highest efficiency possible, since it results in the best mark, as possible. The efficiency was measured by the maximum load on experimental bending testing, divided by the mass of the beam. The results, as well as the interest of the methodology are discussed. It is proved that this methodology can be useful for the students to apply theoretical concepts and, at the same time, to give a deeper understanding of real experimental tests.(undefined)info:eu-repo/semantics/publishedVersio

Bot’n roll robotic kit as a learning tool for youngsters

Activities involving robotics, projecting assembling and programming robots are in essence hands-on and inquiry-based activities leading to an effective learning of different aspects of science and technology among others. Different approaches have being used to introduce robotics in the education of young children. In this communication we will present an approach that in an inquiry based science education, IBSE, perspective, uses an informal environment to introduced robotics, as well as a range of other science and technology, concepts and competencies to young students. Many youngsters are getting interested on general technology and the robotics field in particular. Even though their knowledge is very basic they are very enthusiastic and willing to learn quickly. Most robotics events consist of competitions, and that means the youngsters still need guidance by professionals. RoboParty is a different educational robotics event that teaches the participants, with IBSE hands-on techniques, how to build a robot from scratch to program it and in the end they keep the robot they built for themselves for further exploration. Such robot to be built by the young children for the first time needs to be very easy and with a friendly programming language. The Bot’n Roll robotics kit was developed specifically for the RoboParty event, and has since then been improved with more sensors and actuators, which are simple to built and easy to use. The Bot’n Roll robot family launched recently another more complex robot that uses omnidirectional wheels and that can be used on other robotic competitions like world known RoboCup. This paper describes also the Bot’n Roll robots and show how they are built, bearing in mind that these robots were developed for youngsters who never worked with robotics