3,302 research outputs found
Argamassas multifuncionais para armazenamento de calor, despoluição do ar e auto-limpeza, processo para a sua preparação e utilização
Patente Portuguesa n.º PT 106935A presente invenção diz respeito a argamassas, para aplicação no revestimento interior e exterior de sistemas construtivos, que compreende misturas, em diferentes proporções, de microcápsulas de materiais de mudança de fase (PCM) e nanopartículas de dióxido de titânio, juntamente com um ou mais ligantes, à base de cal, cimento ou gesso, agregados, água e outros materiais auxiliares. A invenção diz também respeito a um processo para a elaboração das referidas argamassas por mistura prévia e homogeneização,
em seco, dos componentes sólidos, com posterior mistura com água e homogeneização numa máquina misturadora. A argamassa de acordo com a invenção é utilizada no revestimento interior e exterior de sistemas construtivos, com o objectivo de poupar energia, melhorar a qualidade do ar e assegurar auto-limpeza.Fundação para a Ciência e a Tecnologia (FCT
Improved Production of Pharmacologically-active Sclerotiorin by Penicillium sclerotiorum
Purpose: The aim of this work was to study the optimum conditions for the production of sclerotiorin, a highly active secondary metabolite of Penicillium sclerotiorum under different cultural media. Methods: A Brazilian strain of P. sclerotiorum was grown under different culture conditions in two liquid media (malt and a dextrose-peptone salt medium supplemented with sodium chloride) and in solid state fermentation in rice. Sclerotiorin production was monitored by high performance liquid chromatography (HPLC). Results: Quantitative analysis of sclerotiorin content by HPLC indicated that sclerotiorin production reached the highest level (up to 313 + 10 mg.L-1) in the dextrose-based medium after 10 days of fermentation. Rice and malt broth showed lower production levels.Conclusion: Enhanced production of P. sclerotiorin for pharmaceutical development can be achieved using dextrose-based cultures.Keywords : Penicillium sclerotiorum, Sclerotiorin,Yield improvement, HPLC, Pharmaceutical industr
Papel de nano-aditivos na funcionalização de argamassas
A manutenção da qualidade do ar no interior dos edifícios é um dos aspetos
mais relevantes da construção sustentável e tem forte impacto no nível de conforto dos
utilizadores. A introdução de nano-aditivos em materiais de construção permite modificar propriedades fundamentais destes materiais convencionais, com o objetivo de proporcionar novas funcionalidades. Neste trabalho apresentam-se os resultados obtidos
com o desenvolvimento de argamassas funcionais que pretendem melhorar a qualidade do ar interior e contribuir para a poupança energética dos edifícios. As formulações foram optimizadas com vista à sua aplicação em construção nova ou reabilitação
Musical Auditory Stimulation and Cardiac Autonomic Regulation
Previous studies have already demonstrated that auditory stimulation with music influences the cardiovascular system. In this study, we described the relationship between musical auditory stimulation and heart rate variability. Searches were performed with the Medline, SciELO, Lilacs and Cochrane databases using the following keywords: “auditory stimulation”, “autonomic nervous system”, “music” and “heart rate variability”. The selected studies indicated that there is a strong correlation between noise intensity and vagal-sympathetic balance. Additionally, it was reported that music therapy improved heart rate variability in anthracycline-treated breast cancer patients. It was hypothesized that dopamine release in the striatal system induced by pleasurable songs is involved in cardiac autonomic regulation. Musical auditory stimulation influences heart rate variability through a neural mechanism that is not well understood. Further studies are necessary to develop new therapies to treat cardiovascular disorders
The effects of auditory stimulation with music on heart rate variability in healthy women
OBJECTIVES: There are no data in the literature with regard to the acute effects of different styles of music on the geometric indices of heart rate variability. In this study, we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of heart rate variability in women. METHODS: We conducted this study in 21 healthy women ranging in age from 18 to 35 years. We excluded persons with previous experience with musical instruments and persons who had an affinity for the song styles. We evaluated two groups: Group 1 (n = 21), who were exposed to relaxant classical baroque musical and excitatory heavy metal auditory stimulation; and Group 2 (n = 19), who were exposed to both styles of music and white noise auditory stimulation. Using earphones, the volunteers were exposed to baroque or heavy metal music for five minutes. After the first music exposure to baroque or heavy metal music, they remained at rest for five minutes; subsequently, they were re-exposed to the opposite music (70-80 dB). A different group of women were exposed to the same music styles plus white noise auditory stimulation (90 dB). The sequence of the songs was randomized for each individual. We analyzed the following indices: triangular index, triangular interpolation of RR intervals and Poincaré plot (standard deviation of instantaneous beat-by-beat variability, standard deviation of the long-term RR interval, standard deviation of instantaneous beat-by-beat variability and standard deviation of the long-term RR interval ratio), low frequency, high frequency, low frequency/high frequency ratio, standard deviation of all the normal RR intervals, root-mean square of differences between the adjacent normal RR intervals and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms. Heart rate variability was recorded at rest for 10 minutes. RESULTS: The triangular index and the standard deviation of the long-term RR interval indices were reduced during exposure to both music styles in the first group and tended to decrease in the second group whereas the white noise exposure decreased the high frequency index. We observed no changes regarding the triangular interpolation of RR intervals, standard deviation of instantaneous beat-by-beat variability and standard deviation of instantaneous beat-by-beat variability/standard deviation in the long-term RR interval ratio. CONCLUSION: We suggest that relaxant baroque and excitatory heavy metal music slightly decrease global heart rate variability because of the equivalent sound level
Properties of lime based thermal mortars
[Excerpt] Nowadays, major part of residential buildings electricity consumption is used for space heating and cooling, varying greatly during day and night and leading to differentiate tariffs. The shift, to off-peak periods, of this consumption presents a clear economical advantage and it can be achieved through energy thermal storage. Latent heat thermal energy storage, through the incorporation of PCM, presents the following advantages: narrow the gap between the peak and off-peak loads, levelling the electricity demand, decreasing the load on the network and eventual supply failure; reduce operation costs by shifting the electrical consumption from peak periods to off-peak periods; contribute to the interior thermal comfort in buildings, by using and storing solar energy (for space heating in winter) and storing natural cooling by ventilation at night during the summer, thus reducing electricity use for heating and cooling [1,2].The benefits to the comfort inside buildings appear during the change of the PCM. The transferences of energy that occur during the transitions solid-liquid and liquid-solid are generally the most used to help the acclimatization of the building. For that reason the PCM must be microencapsulated. The exterior of the microcapsules is made with a polymer [1,2]
Argamassas térmicas à base de cal
Actualmente, as preocupações com o consumo energético dos edifícios são cada
vez maiores. Surgindo desta forma, a necessidade de incorporação de materiais em produtos
de construção que visem a melhoria da eficiência energética dos edifícios. Portanto, a
utilização de materiais de mudança de fase surge como uma possível solução para tentar
solucionar, ou pelo menos minimizar, os enormes consumos energéticos associados aos
edifícios. Este estudo visa o conhecimento da influência da incorporação de microcápsulas
de materiais de mudança de fase (PCM) em argamassas à base de cal, devendo estas possuir
um compromisso entre a trabalhabilidade, resistência mecânica e aparência estética
Novos materiais de construção com tecnologias avançadas
Este artigo pretende apenas dar um contributo, assinalando alguns exemplos em que se
tem vindo a trabalhar e que refletem o uso de tecnologias avançadas na formulação e funcionalidade
de materiais de construção tradicionais. Um exemplo claro é o uso de aditivos que induzem novas
funções e que muitos deles pertencem ao grupo denominado como nanomateriais. A sua adição
coloca quase sempre problemas de incorporação e que requerem um trabalho de ajuste das
formulações e comportamentos no estado fresco ou endurecido. Este trabalho de investigação é
muitas vezes essencial para a otimização das funções que se pretendem que os materiais de
construção venham a demonstrar.
Neste grupo de investigação, resultante da cooperação entre centros de I&D e empresas em projetos
de colaboração diversos ao longo dos últimos anos, tem-se vindo a focar na introdução de novas
funções em materiais de construção tradicionais, para que ganhem um papel ativo em domínios
como o do conforto térmico ou da qualidade ambiental, dois pilares essenciais para uma construção
mais sustentável
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