A relação entre a ciência e a religião num mundo pós-moderno

A ciência auto-suficienteUma ciência com mais humildadeO estatuto do saber científico no pós-modernismoFraquezas do pós-modernismoRazões para uma reaproximação da ciência e da teologia na cultura pós-modernaFactores impeditivos de uma relação profícua entre ciência e religiã

A competitividade de Portugal na educação e na ciência

Encontramo-nos hoje numa sociedade profundamente transformada, em que a velocidade de mudança é cada vez maior. O mundo está atravessado por correntes de ideias e aspirações que se trespassam, misturam e fecundam. Três ou quatro indicadores bastam para ilustrar esta asserção: 18 milhões de desempregados na União Europeia, 1,3 milhões de casos declarados de SIDA através do mundo, 50 milhões de utilizadores da Internet, o equivalente a 2 000 milhões de dólares são negociados em títulos, diariamente, a nível mundial

As relações entre a ciência e a religião na obra do Cardeal Cerejeira

O Contexto de uma ÉpocaA falência do positivismoA nova epistemologia científicaCerejeira precursor de uma epistemologia modernaDEDICATÓRIA EM HOMENAGE

Photophysics of 3-hydroxyflavone in supercritical CO2: a probe to study the microenvironment of SCF

The excitation of 3-hydroxyflavone (3HF) to its second excited singlet state (S2) gives rise to dual fluorescence in supercritical carbon dioxide. The ultraviolet fluorescence originated from the S2 state of 3HF is well separated from the green emission emanating from the tautomeric form, produced via the excited state intramolecular proton transfer. The relative intensity of the S2 to the tautomer fluorescence (S2/T) has been studied as a function of pressure and temperature. It is shown that this ratio reflects the microheterogeneity of the supercritical CO2, and confirms the value of fluorometric probes in disclosing the microscopic properties of supercritical fluids.http://www.sciencedirect.com/science/article/B6TFN-4BVP7G9-3/1/02dd61c567fe3e9c8d6ac86a01f79ce

New Halogenated Phenylbacteriochlorins and Their Efficiency in Singlet-Oxygen Sensitization

Halogenated phenylbacteriochlorins are synthesized with high yields in a two-step procedure. They have strong absorbances in the red and are very stable to air and light at room temperature. Flash photolysis measurements show that the triplet states of these bacteriochlorins have 30 μs lifetimes in deaerated toluene, that are quenched with diffusion-controlled rate constants by molecular oxygen. Time-resolved photoacoustic measurements, with nanosecond and nanocalorie resolution, show that these bacteriochlorins sensitize the formation of singlet oxygen with nearly unity quantum yield. However, singlet-oxygen phosphorescence measurements indicate that physical quenching occurs before the singlet-oxygen molecules diffuse into solution, and nearly half of the sensitized singlet states are lost

Understanding Chemical Reactivity: The Case for Atom, Proton and Methyl Transfers

The concept of ldquochemical reactivityrdquo assumes that atoms and molecules contain the necessary information to describe their evolution over time as they transform from reactants to products. This concept was useful in the past to rationalize reactivity trends and predict the behavior of new systems. Free-energy relationships have played a central role in this field. However, electronic effects often counter the energetic effects and give rise to ldquoanomaliesrdquo or separate correlations. We discuss a quantification of the concept of ldquochemical reactivityrdquo, emphasizing the role of molecular and electronic factors in Chemistry

Nos bastidores da ciência 20 anos depois

Though we might not think so from the media, the strongest area of science in Portugal is actually chemistry — the science of real life, which is also a “green science”, closely connected to the radical transformation of life style that has considerably increased the life expectancy of mankind. Chemistry is not only the domain with the greatest productivity and scientific impact in Portugal, it is also the subject in which we have six universities in the top 1% in the world as regards scientific citations. Irrespective of the personal merit of Sebastião Formosinho and his team, it is not surprising that these scientists, by developing a new theoretical model (ISM) to estimate the velocity of molecular transformations – a model which went against the established knowledge on the subject – have for twenty years been offering a serious challenge to one of the paradigms that won the Nobel Prize in Chemistry in 1992 in the person of Prof. Rudolph Marcus. They also managed to “overcome” Nature when one of their boldest predictions, made in 1991, was confirmed and published in 2006. This effectively ended one round of this scientific battle, although the scientific community was not yet convinced of the validity of these ideas. Recently, however, there have been signs of change as some authorities in the chemistry world were gradually won round. This work offers a glimpse behind the scenes at knowledge in the making, a journey that involves autobiographical details, epistemological and sociological analysis, and scientific controversies, and which outlines the difficulties of producing science and making it past the Portuguese red tape. This is a story of strong contrasts and surprising perspectives, essential for anyone that wishes to understand what it means to be a scientist. The last chapter describes a hospitalization, told from the author’s unique perspective, but with a certain amount of distance and with great humanization – for after all longevity is what comes to mind when we think of any route through the limelight

Nos palcos da ciência: Uma apreciação estética da heterodoxia científica

Em 20 de Setembro de 2013 o autor proferiu a sua “Última Lição” no Departamentode Química da Universidade de Coimbra.Jorge Calado na sua iluminante obra ”Haja Luz” formula uma questão a todosos cientistas: «É preciso não esquecer que a ciência também é bela. [...] O pitoresco,o belo e o sublime representam uma hierarquia de experiências estéticas,de intensidade e qualidade crescente. Será que as ciências obedecem a umahierarquia semelhante?». É em resposta a esta interrogação que o Autor vaipercorrer a sua carreira científica nos domínios mais heterodoxos que cultivou, ena linha de obras como “Nos Bastidores da Ciência. 20 Anos Depois”. Convidaos seus leitores a fazerem uma viagem a diferentes velocidades de percepçãono território da Cinética Química, o domínio da química que trata das velocidadesdas reacções químicas, e em dois veículos teóricos que criou com osseus colaboradores: o “Intersecting-state Model” e a “Teoria de Efeito Túnel”.Em muito, fruto das longas controvérsias científicas que gerou e das quais saiuvencedor, consegue responder de um modo claro ao questionamento colocadopelo seu colega químico, Jorge Calado

Absolute Rate Calculations. Proton Transfers in Solution

The reaction path of the intersecting-state model is used in transition-state theory with the semiclassical correction for tunneling (ISM/scTST) to calculate the rates of proton-transfer reactions from hydrogen-bond energies, reaction energies, electrophilicity indices, bond lengths, and vibration frequencies of the reactive bonds. ISM/scTST calculations do not involve adjustable parameters. The calculated proton-transfer rates are within 1 order of magnitude of the experimental ones at room temperature, and cover very diverse systems, such as deprotonations of nitroalkanes, ketones, HCN, carboxylic acids, and excited naphthols. The calculated temperature dependencies and kinetic isotope effects are also in good agreement with the experimental data. These calculations elucidate the roles of the reaction energy, electrophilicity, structural parameters, hydrogen bonds, tunneling, and solvent in the reactivity of acids and bases. The efficiency of the method makes it possible to run absolute rate calculations through the Internet