188 research outputs found
Effects of the supression partial and total of the frutification on stalks traits of maize cultivars
Neste estudo, objetivou-se avaliar o potencial do colmo de cultivares de milho, quanto ao teor de açúcares e de produção de álcool, em função da supressão parcial e total da frutificação. Pesquisas nesse sentido são desejáveis porque fornecem dados sobre o potencial energético da planta e geram informações sobre processos fisiológicos do milho. O ensaio foi conduzido em Piracicaba, SP, no ano agrícola de 1981/82, utilizando-se o delineamento de blocos casualizados com parcelas subdivididas e seis repetições. Nas parcelas, foram cultivadas oito cultivares, incluindo: um híbrido duplo, dois híbridos simples, e cinco variedades de polinização-livre. Às subparcelas foram aplicados os seguintes tratamentos: a) IP = inflorescência feminina protegida; b) IR = inflorescência feminina removida; c) MV = colheita de milho verde; e d) MM = colheita de milho maduro. Os colmos, colhidos aos 109 dias do plantio, foram avaliados imediatamente após a colheita, quanto a quatorze características. As variedades de polinização-livre (principalmente as populações selecionadas para alto teor de açúcares no colmo) foram superiores aos híbridos, para a maioria das características avaliadas. Os tratamentos IP, IR e MV não diferiram entre si e superaram o tratamento MM, quanto às seguintes características: produção de álcool, sacarose real em percentagem do caldo, e sacarose aparente, açúcares redutores, açúcares totais e sólidos solúveis, em percentagem do caldo e do peso fresco do colmo. Os resultados obtidos sugerem que seria vantajoso o cultivo do milho para produção de milho verde, com a utilização dos colmos para a produção de álcool.A study was carried out to evaluate the potential of the stalks of maize cultivars for both sugar content and alcohol production, as influenced by partial and total supression of the frutification. The informations obtained are considered important not only to know more about the energetic potential, but also increase the knowledge of the physiologic processes of the corn plant. The experiment was carried out in Piracicaba, São Paulo State, Brazil, during the 1980/81 growing season, using a randomized block design with split-plots and six replications. Plots were represented by eight cultivars as follows: one double cross, two single crosses, and five open-pollinated populations. The following treatments were applied to sub-plots: female shoots protected to avoid pollination (SP); female shoots removed (SR); ears at the milks stage removed (GC); and mature kernels produced (MC). Stalks were analized immediately after harvest. In general, the open-pollinated varieties (mainly the populations selected for high sugars in the stalks) were superior to the hybrids for most of the tecnological traits evaluated. The SP, SR, and GC treatments did not differ and were superior to the MC treatment for most of the traits studied. The results obtained in this study suggest the possibility of producing corn at milk stage for human consumption with utilization of the stalks for alcohol production
Influence of different adhesion strategies on glass fiber post retention
Failures in glass fiber post (GFP) retention may be associated with low adhesion achieved in root dentin.55 single-rooted premolars were endodontically treated and distributed according to different adhesion strategies (n=11): G1: RelyX ARC (3M ESPE; etch-rinse strategy); G2: Relyx Ultimate (3M ESPE; etch-rinse strategy); G3: AllCem (FGM; etch-rinse strategy); G4: Relyx Ultimate (3M ESPE; self-etching strategy); G5: RelyX U200 (3M ESPE; self-adhesive strategy). For Bonding Strength (BS) analysis, the roots were sectioned in slices (1.0mm thickness) corresponding to each root third and submitted to push-out test. The type of failure was assessed by scanning electron microscopy (SEM).The highest BS averages were found in G2 and G3. However, in the middle and apical root thirds, G3 showed statistically similar results to G4 and G5. In the cervical and middle third, G1 was statistically similar to G4 and G5. The mixed type of failure was the most common in all groups.Self-etching (G4) and self-adhesive resin (G5) cements, showed similar BS results of immediate bonding in the cementation of GFP compared to conventional resin cements (G1, G2, G3)
The Effect of Depth on Drag During the Streamlined Glide: A Three-Dimensional CFD Analysis
The aim of this study was to analyze the effects of depth on drag during the streamlined glide in swimming using Computational Fluid Dynamics. The Computation Fluid Dynamic analysis consisted of using a three-dimensional mesh of cells that simulates the flow around the considered domain. We used the K-epsilon turbulent model implemented in the commercial code Fluent(®) and applied it to the flow around a three-dimensional model of an Olympic swimmer. The swimmer was modeled as if he were gliding underwater in a streamlined prone position, with hands overlapping, head between the extended arms, feet together and plantar flexed. Steady-state computational fluid dynamics analyses were performed using the Fluent(®) code and the drag coefficient and the drag force was calculated for velocities ranging from 1.5 to 2.5 m/s, in increments of 0.50m/s, which represents the velocity range used by club to elite level swimmers during the push-off and glide following a turn. The swimmer model middle line was placed at different water depths between 0 and 1.0 m underwater, in 0.25m increments. Hydrodynamic drag decreased with depth, although after 0.75m values remained almost constant. Water depth seems to have a positive effect on reducing hydrodynamic drag during the gliding. Although increasing depth position could contribute to decrease hydrodynamic drag, this reduction seems to be lower with depth, especially after 0.75 m depth, thus suggesting that possibly performing the underwater gliding more than 0.75 m depth could not be to the benefit of the swimmer.info:eu-repo/semantics/publishedVersio
Tree canopy enhances Collembola functional richness and diversity across typical habitats of the Gorongosa National Park (Mozambique)
ABSTRACT: The role of tree canopies in protecting soil functional diversity is essential for ecosystems threatened by the longer lasting periods of drought, which are predicted to increase in the southern afro-tropical region. Nonetheless, biodiversity inventories of soil mesofauna are scarce in afro-tropical ecosystems, even in emblematic and well-studied protected areas, such as the Gorongosa National Park (GNP). Understanding the interrelationships between tree canopies and soil fauna functional diversity can provide insightful information for future adaptive management to protect wildlife and ecosystem services in the GNP, in the context of climate change. Here we assessed collembolan functional type richness and functional diversity in the dry period and during the rainfall across major GNP habitat types: miombo forests, mixed forests, and open savanna/floodplains. Besides the significant positive influence of rainfall, habitat types also influenced functional type’ richness and diversity of collembolan life-forms. Environmental gradients across habitat types, namely the area of tree canopy cover and its indirect effect on soil local conditions (pH and nutrient availability), explained collembolan functional parameters. Calcium concentrations and soil alkalinity significantly enhanced collembolan functional type richness and functional diversity, respectively. Collembola survival across GNP habitats depended on the canopy buffering in the dry sampling period. These results highlight the key role of tree canopies in creating suitable microhabitat conditions supporting soil functional diversity and the sustainability of soil processes and ecosystem services in GNP.info:eu-repo/semantics/publishedVersio
Desenvolvimento de um potenciostato de baixo custo para ser empregado em aulas experimentais de Eletroquímica / Development of a low cost potentiostat to be used in experimental classes of Electrochemistry
As atividades experimentais são apontadas como uma importante ferramenta para auxiliar na construção do conhecimento científico durante a formação discente. No entanto, muitas vezes, por falta de reagentes e equipamentos adequados, tais atividades são pouco exploradas nas escolas. Diante disso, este artigo relata a produção de um potenciostato de baixo custo realizada por alunos do curso Técnico Integrado em Mecatrônica do Instituto Federal de Santa Catarina (IFSC – Câmpus Criciúma). O potenciostato é um dispositivo que pode ser utilizado na determinação qualitativa e quantitativa de diferentes espécies químicas através da aplicação de potencial/corrente. Medidas de voltametria cíclica foram realizadas para testar o desempenho do protótipo desenvolvido. Os resultados obtidos apontaram que o potenciostato proposto pode ser satisfatoriamente utilizado em aulas experimentais de Eletroquímica. O custo final do protótipo foi de aproximadamente 230,00 reais, valor muito abaixo de um equipamento comercializado
The Use of an Improved Intragastric Balloon Technique to Reduce Weight in Pre-obese Patients—Preliminary Results
Impact of citrate and lipid-functionalized magnetic nanoparticles in dehydropeptide supramolecular magnetogels: properties, design and drug release
Currently, the nanoparticle functionalization effect on supramolecular peptide-based hydrogels remains undescribed, but is expected to affect the hydrogels' self-assembly and final magnetic gel properties. Herein, two different functionalized nanoparticles: citrate-stabilized (14.4 ± 2.6 nm) and lipid-coated (8.9 ± 2.1 nm) magnetic nanoparticles, were used for the formation of dehydropeptide-based supramolecular magnetogels consisting of the ultra-short hydrogelator Cbz-L-Met-Z-ΔPhe-OH, with an assessment of their effect over gel properties. The lipid-coated nanoparticles were distributed along the hydrogel fibers, while citrate-stabilized nanoparticles were aggregated upon gelation, which resulted into a heating efficiency improvement and decrease, respectively. Further, the lipid-coated nanoparticles did not affect drug encapsulation and displayed improved drug release reproducibility compared to citrate-stabilized nanoparticles, despite the latter attaining a stronger AMF-trigger. This report points out that adsorption of nanoparticles to hydrogel fibers, which display domains that improve or do not affect drug encapsulation, can be explored as a means to optimize the development of supramolecular magnetogels to advance theranostic applications.Ministerio de Economía y Competitividad (MINECO, Spain) under the Grant (CTM2017-84050-R), Xunta de Galicia/FEDER (IN607A 2018/5 and Centro Singular de Investigación de Galicia accreditation 2019-2022, ED431G 2019/06), 0712_ACUINANO_1_E, 0624_2IQBIONEURO_6_E and NANOCULTURE cofounded by FEDER through the program Interreg V-A España-Portugal (POCTEP), NANOCULTURE (ERDF: 1.102.531) Interreg Atlantic Area, the European Union (European Regional Development Fund-ERDF)
Yield and vegetative growth of cactus pear at different spacings and under chemical fertilizations
Efeitos da aplicação de doses de nitrogênio e densidades de plantio sobre os rendimentos de espigas verdes e de grãos de milho
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