Innovative low noise surfaces : comparison of damping and absorption

While sound absorption is an acoustic related property reasonably well known and currently used to characterize low noise surfaces, damping is a property commonly used in other domains to define the energy dissipation of a material but rarely used to characterize this important mechanism in road pavements. This paper compares noise related properties such as damping and absorption of five road pavement surfaces. Two of which are innovative and therefore expected to be low noise since they have high voids content, incorporate fine grading aggregates and expanded clay. Other two incorporate rubber and waste high-density polyethylene giving them an elastic and stiff behaviour respectively. The fifth is a conventional material, asphalt concrete, used for control. Sound absorption tests and mechanical impedance tests were carried out in 30x30 cm slabs at 20ºC. To measure absorption, an impedance tube with an open end was put on the surfaces. To determine damping, the response of a hammer impact measured by an accelerometer on suspended slabs was analysed. Results show that the innovative surfaces have better acoustic related properties while the surface with high-density polyethylene provided the worst results. Furthermore, a strong correlation of damping and air voids was found.(undefined

A reabilitação da rede rodoviária no século XXI : a contribuição da inovação para uma visão global da reabilitação rodoviária

Este artigo aborda a temática da reabilitação da rede rodoviária no contexto dos seus desafios para o futuro próximo. Inicialmente é feita uma abordagem da prática corrente dos processos seguidos na reabilitação e do seu impacto nos custos do ciclo de vida dos pavimentos. A seguir apresenta-se uma visão global da contribuição da reabilitação para a qualidade de vida. Por fim aborda-se o papel da inovação na engenharia rodoviária ao serviço da sociedade, compreendendo a inovação ao nível da qualidade de circulação e a construção e conservação sustentável dos pavimentos rodoviários

Plastic waste use as aggregate and binder modifier in open-graded asphalts

Road pavements are very important infrastructures for the Society, but they can cause serious environmental impacts during construction, operation and rehabilitation phases. Thus, it is essential to develop surface paving solutions that promote not only the durability but also a comfortable and safe use. In fact, this work aims to study the properties of new opengraded mixtures for surface layers produced with plastic wastes. First, HDPE and EVA wastes were used as bitumen modifiers, and then another plastic waste (PEX) replaced part of the aggregates. After studying the modified binders, the open-graded mixtures were designed, and then they were tested concerning their particle loss, rutting resistance, surface texture and damping effect. It was concluded that both ways of using the plastic wastes can improve the mechanical and functional properties of the open-graded mixtures related to the pavement performance.ERDF funds through the Operational Competitiveness Program – COMPETE and the National funds by FCT – Portuguese Foundation for Science and Technology in the scope of PLASTIROADS Project FCOMP-01-0124-FEDER-020335 (PTDC/ECM/119179/2010)

Utilização de nanopartículas de TIO2 para o desenvolvimento de pavimentos rodoviários com capacidade fotocatalítica

A utilização de nanomateriais na indústria de construção rodoviária representa uma opção estrategicamente inovadora que visa a modificação dos materiais convencionais. Neste âmbito, dotar a superfície dos pavimentos rodoviários de capacidade fotocatalítica contribuirá para efetuar a despoluição do ar e a redução da sujidade adsorvida nestas superfícies, aumentando a segurança rodoviária uma vez que minimiza a presença de óleos e gorduras adsorvidos pelas mesmas. Neste trabalho, misturas asfálticas convencionais foram modificadas pela adição de nanopartículas de TiO2 através de dois processos diferentes: inclusão em volume e por aspersão superficial de uma solução aquosa de nanopartículas de TiO2. As misturas asfálticas foram caracterizadas quimicamente e a sua morfologia e capacidade fotocatalítica foram avaliadas. Os resultados obtidos demonstram que a utilização de nanopartículas de TiO2 (aplicadas na superfície pela técnica de aspersão) permitiu obter misturas asfálticas com elevada capacidade fotocatalítica, já que o rendimento de fotodegradação foi superior a 50%.FEDE

2,4,5-Triaminopyrimidines as blue fluorescent probes for cell viability monitoring: synthesis, photophysical properties, and microscopy applications

Monitoring cell viability is critical in cell biology, pathology, and drug discovery. Most cell viability assays are cell-destructive, time-consuming, expensive, and/or hazardous. Herein, we present a series of newly synthesized 2,4,5-triaminopyrimidine derivatives able to discriminate between live and dead cells. To our knowledge, these compounds are the first fluorescent nucleobase analogues (FNAs) with cell viability monitoring potential. These new fluorescent molecules are synthesized using highly efficient and cost- effective methods and feature unprecedented photophysical properties (longer absorption and emission wavelengths, environment-sensitive emission, and unprecedented brightness within FNAs). Using a live– dead Saccharomyces cerevisiae cell and theoretical assays, the fluorescent 2,4,5-triaminopyrimidine derivatives were found to specifically accumulate inside dead cells by interacting with dsDNA grooves, thus paving the way for the emergence of novel and safe fluorescent cell viability markers emitting in the blue region. As the majority of commercially available viability dyes emit in the green to red region of the visible spectrum, these novel markers might be useful to meet the needs of blue markers for co-staining combinations

Perspectivas do ensino de Geociências

The teaching of Science was incorporated into school curricula only in the nineteenth century. In Imperial Brazil, the teaching of the natural sciences was incipient, although, since the creation of the Colégio Pedro II in 1837, Science was already part of the curriculum of secondary education. But only in the second half of the last century the earliest courses in Geosciences (Geology, Geophysics, Meteorology, and Oceanography) began to be created. Currently, there are courses in these modalities across the country. However, there are serious obstacles for teaching to evolve in keeping with the current needs of the professional market and the trends imposed by technological advances. In this work, we analyze obstacles and professional gaps in Higher Education, and highlight some educational practices capable of improving learning and which could be universalized. It is no longer possible to put off the expansion of the area of Geosciences in teacher training and qualification courses for Basic Education. This article brings together some essential factors to achieve this goal.O ensino de Ciências foi incorporado aos currículos escolares somente no século XIX. No Brasil-Império o ensino das Ciências Naturais era incipiente, embora ciências já fizessem parte do currículo do ensino secundário desde a criação do Colégio Pedro II, em 1837. Os primeiros cursos de nível superior em Geociências (Geologia, Geofísica, Meteorologia e Oceanografia) começaram a ser criados somente a partir da segunda metade do século passado. Atualmente, há cursos nessas modalidades em todo o país, que enfrentam, contudo, sérios obstáculos para que o ensino evolua de acordo com as necessidades atuais do mercado de trabalho, e das tendências impostas pelo avanço tecnológico. Neste trabalho analisamos entraves e lacunas profissionais no Ensino Superior e destacamos algumas práticas educacionais capazes de melhorar o aprendizado, que poderiam ser universalizadas. É inadiável expandir a área de Geociências nos cursos de formação e capacitação de professores para a Educação Básica; o artigo reúne alguns fatores essenciais para atingir essa meta

Ensino de Geociências na universidade

In colonial times, in Brazil, although intense mining activities occurred in the search for gold and diamonds, relevant geoscientific actions did not occur. In the 19th century, a few geological exploratory trips were made, from which several written contributions resulted. Moreover, important institutions were created, such as the National Observatory, the Meteorological Service, the Magnetic Observatory at Vassouras and the Mining School of Ouro Preto in 1876, The formal teaching of Geosciences in Brazil started only in 1957, with the ”Campaign for the training of geologists” (CAGE), that created and provided material and human resources to four Geology undergraduate courses. In Meteorology the first course was in 1973, in Oceanography in 1971 and in Geophysics in 1983. Now, 48 Brazilian universities offer 71 undergraduate courses in Geosciences, 33 in Geology, 3 in Geological Engineering, 14 in Meteorology, 13 in Oceanography and 8 in Geophysics. Fifty-seven graduate programs exist in Brazil, 13 of which are considered of excellence, indicating that the area is mature and consolidated. Most geologists and geophysicists were absorbed in geological mapping activities, as well as mining and oil exploration. Meteorologists dedicated themselves to meteorological and climatic monitoring, as well as to projects in hydroelectric, wind and solar energy. Graduates in Oceanography worked in institutions related to the environment, agriculture, and to the Ministry of the Navy. The atmospheric and oceanographic sciences are of global relevance in studies of climatic changes and global warming. In turn, the major challenge of geologists and geophysicists is to improve knowledge of the Brazilian territory, at the local and regional scale.No Brasil colonial, apesar de intensa atividade mineira na busca de ouro e diamantes, não houve práticas geocientíficas relevantes. No século XIX ocorreram diversas explorações geológicas, das quais resultou uma vasta contribuição escrita. Além disso foram criadas importantes instituições, como o Observatório Nacional, o Serviço Meteorológico, o Observatório Magnético de Vassouras e a Escola de Minas de Ouro Preto em 1876. O ensino formal de Geociências no Brasil foi iniciado apenas em 1957, com a Campanha de Formação de Geólogos (CAGE), que criou e forneceu recursos materiais e humanos para quatro cursos de graduação em Geologia. Na Meteorologia a graduação se iniciou em 1963, na Oceanografia em 1971, e na Geofísica em 1983. Atualmente, 47 universidades brasileiras oferecem 71 cursos de graduação nas Geociências. Há 33 cursos de Geologia, três de Engenharia Geológica, 14 de Meteorologia, 13 de Oceanografia e 8 de Geofísica. Há no Brasil 57 programas de pós-graduação em Geociências, 13 dos quais considerados de excelência, indicando que a situação atual da área é de consolidação e maturidade. Geólogos e geofísicos foram absorvidos, em sua maioria, pelas atividades de mapeamento geológico, exploração mineral e de petróleo. Meteorologistas dedicaram-se ao monitoramento meteorológico e climático, e também a projetos de energia hidroelétrica, eólica e solar. Na Oceanografia, os formados atuaram em órgãos relacionados com ambiente, agricultura e no Ministério da Marinha. Quanto à pesquisa, as ciências atmosféricas e oceanográficas são de grande relevância global, no estudo das mudanças climáticas e o aquecimento global. Por sua vez, o maior desafio de geólogos e geofísicos é o de melhorar do conhecimento do território brasileiro, na escala local ou regional

Spintronic devices for biomedical applications

Spintronic devices have been proposed over the past decade for various biomedical applications. These include static or dynamic biomolecular recognition platforms ( DNA-cDNA, antibody-antigen, phage-bacteria, ), cytometer and cell separation devices and lateral bio assay platforms , microelectrode based devices for neuroelectronic applications, and hybrid sensor arrays for imaging applications [1]. The biomolecular recognition platforms include a magnetoresistive sensor array, a set of biomolecular probes ( surface immobilized or in solution) , biological targets labeled with particular magnetic micro beads or magnetic nanoparticles, and arraying architectures and microfluidics used to increase sensitivity and favour probe-target interaction. The platforms also incorporate the proper signal conditioning and processing electronics. Results will be shown for cell free DNA detection as a cancer marker indicator, and for cell detection using phage markers. For neuroelectronic applications, magnetoresistive sensors were fabricated onto Si microelectrode arrays. Experiments probe either extra cellular currents measured in mouse hypocampus slices, or spinal medulla signals probed directly with implanted magnetoresistive electrodes. For deep brain simulation and detection, sensors and electrodes are being fabricated into flexible polyimide probes. Separation between straight electrical contributions and magnetic signals is discussed. For imaging applications ( magneto cardiography) efforts continue to reach pT level detectivity at 1Hz, using hybrid MEMS/magnetoresistive sensor devices. Two architectures will be presented leading to larger DC field mechanical modulation, and therefore increased sensitivity

Challenges in spintronic platforms for biomedical applications

Integrated spintronic biochip platforms are being developed for portable, point-of-care, diagnostic and cytometric applications [1,2]. Hybrid systems incorporating magnetoresistive sensors are applied to neuroelectronic studies and biomedical imaging, namely magnetoencephalography and magnetocardiography. Lab-on-a-chip MR-based platforms are under development to perform biological studies at the single molecule level. This review introduces and discusses the potential and main characteristics of those MR-based biomedical devices, comparing to the existing technologies, while giving particular examples of targeted applications. Applications to the detection of DNA hybridization events (DNA-chips) [3] and antibody-antigen recognition at immunoassays (immuno-chips) [4] are discussed. Particular examples for cell free DNA and genomic sequences detection, for pathogen (Salmonella enteritidis, see Fig.1) detection and for flow cytometry (separation and counting) of CD34+ magnetically labeled cells coming from bone marrow or cord blood samples are given. Moreover, lateral immuno-assay configurations where analytes are labeled with magnetic nanoparticles are discussed. For biomedical imaging applications, field sensitivity is being pushed towards 1pT/sqrt(Hz) and below in hybrid devices incorporating flux guides with the magnetoresistive element allowing the direct detection of bio-magnetic fields (from brain and heart). For neuroelectronic applications, sensors are being incorporated in microelectrode arrays (Si and polyimide) to record spontaneous or stimulated neural activity (in vitro and in vivo, see Fig.2)