243 research outputs found

    Avaliação energética de um sistema híbrido radiante-convectivo a dois-tubos, ventiloconvectores e paredes radiantes

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    A comparação dos sistemas radiantes com os sistemas convectivos tradicionais pode ser efectuada através da análise comparativa dos efeitos resultantes da elevação da temperatura radiante média e 1 K com os efeitos resultantes da elevação da temperatura do ar interior de 1 K. No presente artigo, introduz-se um sistema híbrido radiante-convectivo baseado no sistema a dois-tubos, ventiloconvectores e paredes radiantes para um edifício de escritórios. Com base no programa de simulação DOE2, obtém-se a poupança energética anual devida à alteração da temperatura do ar no interior da sala de 1 K nas estações de aquecimento e arrefecimento e apresentam-se resultados que demonstram que o consumo energético para a alteração de 1 K da temperatura radiante média é inferior a esta poupança energética. Discutem-se questões técnicas e relativas ao investimento necessário para implementar o sistema híbrido radiante-convectivo. Os resultados permitem concluir o interesse deste sistema híbrido radiante-convectivo

    Análise das propostas de revisão do zoneamento bioclimático brasileiro: estudo de caso de Colatina, ES

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    Resumo O desenvolvimento de zonas bioclimáticas permite a elaboração de estratégias direcionadas para a construção de edifícios que sejam adequados a cada zona particular. No Brasil a NBR 15220-03:2005 apresenta o zoneamento bioclimático brasileiro e as diretrizes construtivas para habitações unifamiliares de interesse social. Porém, desde sua publicação pesquisadores defendem a necessidade de uma revisão no zoneamento referindo, especialmente, a imprecisão na caracterização climática de cidades brasileiras. Por ser a única classificação climática no país, seu uso não se restringe às habitações de interesse social, sendo usada também para outras tipologias, o que reforça a necessidade de revisão. Com a contribuição destes pesquisadores, várias propostas surgiram para a revisão do atual zoneamento. O objetivo é discutir as várias propostas de zoneamento bioclimático brasileiro, tanto a da NBR 15220-3 quanto as propostas de revisão, mediante a aplicação delas à região de Colatina, ES. O método da pesquisa consistiu em aplicar dados dos arquivos climáticos de Colatina a cada uma das metodologias empregadas nas definições de zoneamento bioclimático. As análises mostraram que o método escolhido interfere diretamente na classificação climática de Colatina, fazendo com que a região estudada seja classificada na mesma zona climática, ou em zonas diferentes, das cidades próximas

    Performance effects of internal pre- and per-cooling across different exercise and environmental conditions: A systematic review

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    Exercise in a hot and humid environment may endanger athletes health and affect physical performance. This systematic review aimed to examine whether internal administration of ice, cold beverages or menthol solutions may be beneficial for physical performance when exercising in different environmental conditions and sports backgrounds. A systematic search was performed in PubMed, Web of Science, Scopus and SPORTDiscus databases, from inception to April 2022, to identify studies meeting the following inclusion criteria: healthy male and female physically active individuals or athletes (aged 18 years); an intervention consisting in the internal administration (i.e., ingestion or mouth rinse) of ice slush, ice slurry or crushed ice and/or cold beverages and/or menthol solutions before and/or during exercise; a randomized crossover design with a control or placebo condition; the report of at least one physical performance outcome; and to be written in English. Our search retrieved 2,714 articles in total; after selection, 43 studies were considered, including 472 participants, 408 men and 64 women, aged 18-42 years, with a VO2max ranging from 46.2 to 67.2 mLkg1min1. Average ambient temperature and relative humidity during the exercise tasks were 32.4 ± 3.5°C (ranging from 22°C to 38°C) and 50.8 ± 13.4% (varying from 20.0% to 80.0%), respectively. Across the 43 studies, 7 exclusively included a menthol solution mouth rinse, 30 exclusively involved ice slurry/ice slush/crushed ice/cold beverages intake, and 6 examined both the effect of thermal and non-thermal internal techniques in the same protocol. Rinsing a menthol solution (0.01%) improved physical performance during continuous endurance exercise in the heat. Conversely, the ingestion of ice or cold beverages did not seem to consistently increase performance, being more likely to improve performance in continuous endurance trials, especially when consumed during exercises. Co-administration of menthol with or within ice beverages seems to exert a synergistic effect by improving physical performance. Even in environmental conditions that are not extreme, internal cooling strategies may have an ergogenic effect. Further studies exploring both intermittent and outdoor exercise protocols, involving elite male and female athletes and performed under not extreme environmental conditions are warranted.Systematic review registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021268197], identifier [CRD42021268197]

    Legume biofortification and the role of plant growth-promoting bacteria in a sustainable agricultural era

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    World population growth, together with climate changes and increased hidden hunger, bring an urgent need for finding sustainable and eco-friendly agricultural approaches to improve crop yield and nutritional value. The existing methodologies for enhancing the concentration of bioavailable micronutrients in edible crop tissues (i.e., biofortification), including some agronomic strategies, conventional plant breeding, and genetic engineering, have not always been successful. In recent years, the use of plant growth-promoting bacteria (PGPB) has been suggested as a promising approach for the biofortification of important crops, including legumes. Legumes have many beneficial health effects, namely, improved immunological, metabolic and hormonal regulation, anticarcinogenic and anti-inflammatory effects, and decreased risk of cardiovascular and obesity-related diseases. These crops also play a key role in the environment through symbiotic nitrogen (N) fixation, reducing the need for N fertilizers, reducing CO2 emissions, improving soil composition, and increasing plant resistance to pests and diseases. PGPB act by a series of direct and indirect mechanisms to potentially improve crop yields and nutrition. This review will focus on the: (i) importance of legumes in the accomplishment of United Nations Sustainable Development Goals for production systems; (ii) understanding the role of PGPB in plant nutrition; (iii) iron biofortification of legumes with PGPB, which is an interesting case study of a green technology for sustainable plant-food production improving nutrition and promoting sustainable agriculture.info:eu-repo/semantics/publishedVersio

    Tungsten in barium stars

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    Classical barium stars are red giants that received from their evolved binary companions material exposed to the \textit{slow} neutron-capture nucleosynthesis, i.e., the ss-process. Such a mechanism is expected to have taken place in the interiors of Thermally-Pulsing Asymptotic Giant Branch (TP-AGB) stars. As post-interacting binaries, barium stars figure as powerful tracers of the ss-process nucleosynthesis, evolution of binary systems, and mechanisms of mass transfer. The present study is the fourth in a series of high-resolution spectroscopic analyses on a sample of 180 barium stars, for which we report tungsten (W, Z=74Z=74) abundances. The abundances were derived from synthetic spectrum computations of the W\,{\sc i} absorption features at 4\,843.8~\AA\ and 5\,224.7~\AA. We were able to extract abundances for 94 stars; the measured [W/Fe] ratios range from 0.0\sim0.0 to 2.02.0 dex, increasing with decreasing of metallicity. We noticed that in the plane [W/Fe] versus [ss/Fe] barium stars follow the same trend observed in post-AGB stars. The observational data were also compared with predictions of the {\sc fruity} and Monash AGB nucleosynthesis models. These expect values between 0.20-0.20 and +0.10+0.10 dex for the [W/hs] ratios, whereas a larger spread is observed in the program stars, with [W/hs] ranging from 0.40-0.40 to +0.60+0.60 dex. The stars with high [W/hs] ratios may represent evidence for the operation of the intermediate neuron-capture process at metallicities close to solar.Comment: 11 pages, 4 figures, accepted for publication in MNRA

    High-resolution spectroscopic analysis of four new chemically peculiar stars

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    We present detailed chemical compositions of four stars on the first-ascent red giant branch that are classified as chemically peculiar, but lack comprehensive analyses at high spectral resolution. For BD+03{\deg}2688, HE 0457-1805, HE 1255-2324, and HE 2207-1746, we derived metallicities [Fe/H] =1.21=-1.21, 0.19-0.19, 0.31-0.31, and 0.55-0.55, respectively, indicating a range in Galactic population membership. In addition to atmospheric parameters, we extracted elemental abundances for 28 elements, including the evolutionary-sensitive CNO group and 12^{12}C/13^{13}C ratios. Novel results are also presented for the heavy elements tungsten and thallium. All four stars have very large enhancements of neutron-capture elements, with high [La/Eu] ratios indicating enrichments from the slow neutron capture (ss-process). To interpret these abundances, all indicative of [ss/Fe] >1.0> 1.0, we compared our results with data from literature, as well as with predictions from the Monash and FRUITY ss-process nucleosynthesis models. BD+03{\deg}2688, HE 1255-2324, and HE 2207-1746 show C/O >1>1, while HE 0457-1805 has C/O <1<1. Since HE 0457-1805 and HE 1255-2324 are binary stars, their peculiarities are attributable to mass transfer. We identified HE 0457-1805 as a new barium giant star, and HE 1255-2324 as a new CH star, in fact a higher metallicity analogue CEMP-r/sr/s star; the single object reported in literature so far with similar characteristics is the barium star HD 100503 ([Fe/H] =0.72= -0.72). A systematic monitoring is needed to confirm the binary nature of BD+03{\deg}2688 and HE 2207-1746, which are probably CH stars.Comment: 33 pages, 24 figures, accepted for publication in MNRA

    Study of symptoms and gene expression in four Pinus species after pinewood nematode infection

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    Pine wilt disease, caused by the pinewood nematode Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle, is originating severe infections in pine trees. The disease is detected when external symptoms appear (e.g. needle chlorosis), but trees could remain asymptomatic for long periods and serve as a long-term host. The primary goal of this study was to assess the effect of inoculation with an avirulent isolate of B. xylophilus (C14-5) on different Pinus spp. seedlings (P. sylvestris, P. nigra, P. pinea and P. pinaster). At the same time, seedlings were also inoculated with a virulent strain, HF, in order to compare the phenotypic and genomic results of the two types of inoculations. The effect of inoculation was determined in terms of expression of various Pinus genes potentially involved in the response to the disease.The results suggest that P. pinea and P. nigra are more resistant to infection by the nematode than P. sylvestris and P. pinaster. The phenotypic and genetic differences were more marked among P. pinea and P. pinaster.info:eu-repo/semantics/acceptedVersio

    Prevalence and pattern of cognitive impairment in rural and urban populations from Northern Portugal

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    <p>Abstract</p> <p>Background</p> <p>Despite worldwide recognition of the burden of dementia, no epidemiological data is yet available in Portugal. The objective of this study is to estimate the prevalence and describe the pattern of cognitive impairment with dementia or no dementia (CIND) in rural and urban populations from Northern Portugal.</p> <p>Methods</p> <p>Two random samples of residents aged 55 to 79 years in rural and urban communities were drawn from the health centres registries to be screened for cognitive impairment. The screening criteria for dementia were an abnormal Mini-Mental State Examination (MMSE) score or a Blessed Dementia Scale score. After excluding those who tested positive for dementia, cut-off points for CIND were set at 1 standard deviation below the mean of the MMSE according to educational level. All those who screened positive either for dementia or CIND were examined by a neurologist for establishing a definitive diagnosis.</p> <p>Results</p> <p>The prevalence of cognitive impairment was higher in rural than in urban populations, 16.8% (95% CI: 14.3-19.8%) vs. 12.0% (95%CI: 9.3-15.4%), with a rural/urban prevalence ratio (PR) of 2.16 (95% CI: 1.04-4.50) in the eldest and 2.19 (95% CI: 1.01-4.76) in persons with vascular risk factors. The prevalence of dementia was 2.7% (95% CI: 1.9-3.8%) with a rural/urban PR = 2.1 and the prevalence of CIND was 12.3% (95% CI: 10.4-14.4%) and PR = 1.3. The prevalence of dementia increases exponentially with age and in those with cerebrovascular disease or other comorbid conditions while the prevalence of CIND, besides these factors, is also higher in persons with low levels of education or vascular risk factors. Alzheimer's and vascular disease were equally likely aetiologies of dementia (38.7%), the later more common in men PR(F:M = 0.3) as opposed to the former PR(F:M = 2.0). Vascular CIND, associated either with cerebrovascular disease or vascular risk factors was more frequent (39.7%) then depression (18.4%) or any other aetiology.</p> <p>Conclusions</p> <p>The prevalence of cognitive impairment is higher in rural compared with urban populations. This is shown in the synergy between age and rurality, with the rural/urban prevalence ratio increasing with age. In this relatively young population from Northern Portugal, cerebrovascular disease as well as vascular risk factors account for 48% of overall cognitive impairment.</p
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