84 research outputs found
Synthesis and characterization of nanostrctured V2O5nH2O prepared throughout the hydrothermal method.
Nitrogen doping of TiO2 photocatalyst forms a second eg state in the Oxygen (1s) NEXAFS pre-edge
Close inspection of the pre-edge in oxygen near-edge x-ray absorption fine
structure spectra of single step, gas phase synthesized titanium oxynitride
photocatalysts with 20 nm particle size reveals an additional eg resonance in
the VB that went unnoticed in previous TiO2 anion doping studies. The relative
spectral weight of this Ti(3d)-O(2p) hybridized state with respect to and
located between the readily established t2g and eg resonances scales
qualitatively with the photocatalytic decomposition power, suggesting that this
extra resonance bears co-responsibility for the photocatalytic performance of
titanium oxynitrides at visible light wavelengths
Cattle production in silvopastoral systems compared to monoculture pasture in the Brazilian Cerrado.
Adoption of silvopastoral systems (SS) in Brazil has been stimulated in the last decade. This work aimed to evaluate beef production under SS with eucalyptus using densities of 178 and 441 trees per ha and to compare it to a traditional monoculture Piatã grass pasture (PM) in the Brazilian Cerrado. Shading caused by the two tree densities, in the third year of the systems implementation did not cause changes neither on forage mass nor on its nutritive value. As consequence, results show that both SS did not differ from the PM for beef cattle production in the period studied, allowing better thermal comfort for grazing cattle, besides wood production and greenhouse gases mitigation
Femtosecond laser processing of glassy and polymeric matrices containing metals and semiconductor nanostructures.
Now you see me, now you don't : a case study of the effect of the sampling method on the perceived struture of Ichthyological communities
Fauna and Flora of the Atlantic Islands : Proceedings of the 3rd Symposium, Ponta Delgada, 21-25-September 1998.The fish community of a small rocky area near Ponta Delgada, Azores, was assessed using two methods: visual census and rotenone collections. The results obtained with each method are analysed and compared. A total of 46 species was recorded for this site. The visual census recorded more species than did the rotenone collections, but each method detected species that escaped the other. The total fish diversity was found to be similar to that reported in other localized studies of littoral rocky areas of the eastern Atlantic and the
Mediterranean. Each method used revealed a different spatial structure and different
trophic relationships of the ichthyological community. The visual census put in evidence
the pelagic/demersal component, while the rotenone collections emphasized the benthic
one. Both methods agree on the importance of the benthic primary production in the
trophic food web. Visual census data further suggest that the relevance of the direct
consumption of algal material by omnivores and herbivores is greater than could be
guessed by the species diversity in this group. Strategies are discussed for combining visual and destructive sampling methods in order to achieve a more accurate representation of a given fish community
Multiple factor analysis to identify correlated variable among microclimate, thermal comfort and infrared thermography in agroforestry systems.
Goal was to use the Multiple Factor Analysis to reduce dimensionality of variables, to identify groups of correlated variables and to obtain a common assessment tool to evaluate microclimate, thermal comfort and infrared thermography in agroforestry systems. The experiment was conducted at the Embrapa Beef Cattle, Campo Grande, MS, from July 2015 to February 2016, corresponding to winter and summer seasons, in two agroforestry systems with different tree densities and spatial arrangements of native and planted trees. Readings were made from 8:00 a.m. to 4:00 p.m., for microclimate parameters (air temperature, dew point temperature, black globe temperature, relative humidity, wind speed, global solar radiation, photosynthetically active radiation and luminosity), thermal comfort (Temperature and Humidity Index, Black Globe and Humidity Index, Radiation Thermal Load), and infrared thermography (temperature and humidity of tree crown and soil surface), under full sun and shadow projection. Multiple Factor Analysis found three Synthetic Analytical Dimensions that explained 55.5% of the total observed variance. Strong and positive associations between infrared thermography, microclimate, thermal comfort and radiation were found. Thus, it is suggested that infrared thermography is a potential tool to be used for microclimate prediction and thermal comfort under agroforestry systems
Vaginal temperature as indicative of thermoregulatory response in Nellore heifers under different microclimatic conditions.
The objective was to evaluate vaginal temperature as a thermoregulatory response of Nellore heifers under different microclimatic conditions. The study was conducted during one year in an experimental area located at 54?370W, 20?270S, and 530 m of altitude in Brazil. Twenty-four Nellore females were reared in integrated crop-livestock-forestry systems with different shading patterns. The randomized complete block experimental design was utilized with a sub subdivided plots scheme, with plot corresponding to the production systems, the subplot to the season of the year, and the sub subplot, the hours of the day. To characterize the microclimate, data regarding air and black globe temperatures, and air relative humidity were collected and from them, temperature-humidity index was calculated. Vaginal temperature was obtained by using a bottom-type temperature logger (i-button) attached to an adapted intravaginal device. The black-globe temperature explained the variation on vaginal temperature. Increases on vaginal temperature were only observed, on average, two hours after the increase of black-globe temperature. The microclimatic conditions found in the systems, resulting from the various tree densities, modify the vaginal temperature in different degrees, demonstrating that the shading effect is not always accompanied by improvements in thermal comfort. The system with intermediate density showed a better microclimatic condition and, consequently, a lower increase in vaginal temperature. The interaction between air temperature, humidity and solar radiation resulted in adverse environmental conditions, however, Nellore heifers showed good adaptation to the environment. In conclusion, vaginal temperature is a good indicator to evaluate the thermoregulatory response in Nellore heifers
Crescimento de árvores nativas de cerrado com potencial de uso na arborização de pastagens.
Edição especial dos resumos do IUFRO World Congress, 25., 2019, Curitiba
Microclima sob a copa de espécies arbóreas nativas do cerrado em arboreto.
O componente florestal em sistemas em integração Lavoura-Pecuária-Floresta (ILPF), proporciona benefícios econômicos e ambientais. Dentre os benefícios ambientais estão alterações no microclima (temperatura, umidade e incidência de radiação). Assim, teve-se como objetivo avaliar os índices de temperatura e umidade e porcentagem de bloqueio de radiação sob a copa de Genipa americana L. (Jenipapo), Peltophorum dubium (Canafístula) e Pterogyne nitens (Amendoim bravo), espécies arbóreas nativas do Cerrado
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