oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 600 )

2018 ( 878 )

2017 ( 849 )

2016 ( 1177 )

Custom range...

Search Results: 1 - 10 of 494632 matches for " S. S. e Almeida Silva "
All listed articles are free for downloading (OA Articles)
Page 1 /494632
Display every page Item
A Study on Ethanolysis and Methanolysis of Coconut Oil for Enzymatically Catalyzed Production of Biodiesel  [PDF]
Livia M. O. Ribeiro, Albanise E. Silva, Margarete C. S. Silva, Renata M. R. G. Almeida
Journal of Sustainable Bioenergy Systems (JSBS) , 2014, DOI: 10.4236/jsbs.2014.44020
Abstract: Biodiesel production by enzymatic catalysis has been the subject of much research for developing processes that can potentially compete with other types of catalysis. The objective of this study was to investigate the variables that influenced the transesterification of coconut oil catalyzed by immobilized lipase for biodiesel production. A full 24 factorial design with the variables tempera-ture (40°C - 60°C), enzyme concentration (3% - 7%), oil-ethanol ratio (1:6 - 1:10) and alcohol type (methanol-ethanol) was performed. The best conversion result (80.5%) was obtained using ethanol with a higher temperature, molar ratio and enzyme concentration. The obtained yields showed that the results attained with ethanol were more significant when compared with methanol.
Scalar field localization on 3-branes placed at a warped resolved conifold
J. E. G. Silva,C. A. S. Almeida
Physics , 2011, DOI: 10.1103/PhysRevD.84.085027
Abstract: We have studied the localization of scalar field on a 3-brane embedded in a six dimensional warped bulk of the form $M_{4}\times C_{2}$, where $M_{4}$ is a 3-brane and $C_{2}$ is a 2-cycle of a six resolved conifold $\mathcal{C}_{6}$ over a $T^{1,1}$ space. Since the resolved conifold is singularity-free in $r=0$ depending on a resolution parameter $a$, we have analyzed the behavior of the localization of scalar field when we vary the resolution parameter. On one hand, this enable us to study the effects that a singularity has on the field. On the other hand we can use the resolution parameter as a fine-tuning between the bulk Planck mass and 3-brane Planck mass and so it opens a new perspective to extend the hierarchy problem. Using a linear and a nonlinear warp factor, we have found that the massive and massless modes are trapped to the brane even in the singular cone ($a\neq 0$). We have also compared the results obtained in this geometry and those obtained in other six-dimensional models, as string-like geometry and cigar-like universe geometry.
Peduncle and fruit yield, in six cropping seasons, of early dwarf cashew tree clones irrigated with different water regimes
Silva, Kathia Maria Barbosa e;Almeida, Francisco Aécio Guedes;Silva, Paulo Sérgio Lima e;
Revista Brasileira de Fruticultura , 2004, DOI: 10.1590/S0100-29452004000300024
Abstract: the objective of this work was to evaluate peduncle and fruit yield in clone ms 076 and in a clonal population of drip-irrigated, early dwarf cashew trees propagated by layering, in six cropping seasons. in order to meet the increased water requirements of the crop resulting from plant growth and development, irrigation during the dry season was performed daily according to the following water regime: 15 min/plant/day during the 1st year, 30 min/plant/day during the 2nd year, 45 min/plant/day during the 3rd year and 60 min/plant/day during all subsequent years. water was supplied by one drip emitter/plant, at an (adjustable) flow rate of 36 l/h.the research was carried out in fortaleza-ceará, brazil, and a random block design was utilized, with five replicates and split-plots. the clones were assigned to plots and the cropping seasons were considered as subplots. the clonal population was superior to the clone only with regard to number of nut shells (nns), and solely in the first season. the clone was superior to the population as to nns and peduncle yield (py) in the second season, and also with regard to the three evaluated traits - nns, py, and nut shell yield, in the last three cropping seasons.
Quaternion-Loop Quantum Gravity
M. D. Maia,S. S. e Almeida Silva,F. S. Carvalho
Physics , 2008, DOI: 10.1007/s10701-009-9350-5
Abstract: It is shown that the Riemannian curvature of the 3-dimensional hypersurfaces in space-time, described by the Wilson loop integral, can be represented by a quaternion quantum operator induced by the SU(2) gauge potential, thus providing a justification for quaternion quantum gravity at the Tev energy scale.
A 6D standing wave Braneworld
L. J. S. Sousa,J. E. G. Silva,C. A. S. Almeida
Physics , 2012,
Abstract: We constructed a six-dimensional version of the standing wave model with an anisotropic 4-brane generated by a phantom-like scalar field. The model represents a braneworld where the compact (on-brane) dimension is assumed to be sufficiently small in order to describe our universe (hybrid compactification). The proposed geometry of the brane and its transverse manifold is non-static, unlike the majority of braneworld models presented in the literature. Furthermore, we have shown that the zero-mode scalar field is localized around the brane. While in the string-like defect the scalar field is localized on a brane with decreasing warp factor, here it was possible to perform the localization with an increasing warp factor.
Propofol-cetamina racêmica e propofol-cetamina levógira em cadelas: parametros eletrocardiográficos e outras variáveis fisiológicas
Almeida, R.M.;Silva, C.E.V.;Zimmermann, M.;Maguilnik, S.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2008, DOI: 10.1590/S0102-09352008000600019
Abstract: the effects of propofol and ketamine on physiological parameters, electrocardiography, and analgesia were evaluated in twelve dogs that received propofol-ketamine (0.4mg/kg/min + 0.2mg/kg/min, n=6, pk group) or propofol-s+ketamine (0.4mg/kg/min + 0.1mg/kg/min, n=6, pks group) after induction of anesthesia with propofol (8.0mg/kg). assessments of pain; heart rate (hr); electrocardiography (ecg); respiratory rate (rr); systolic, medium, and diastolic arterial pressures (sap, map, dap); saturation of hemoglobin (spo2); and rectal temperature (rt) were conducted. there was a rise in hr with no electrocardiographically changes, but an increase in amplitude of t wave in one animal of each group. rr decreased and spo2 were lower than 90% in two moments of both groups. sap, map, and dap were reduced during the experimental period, but with no statistical difference between the protocols. there was no analgesia in seven bitches, mild analgesia was observed in three, and satisfactory analgesia in only two animals tested. it was concluded that the protocols are safe for dogs, but there is no analgesia for surgical procedures. the changes in ecg are related to hr and amplitude of t wave, which may be due to myocardial hypoxia.
Utiliza??o de mostos concentrados na produ??o de cervejas pelo processo contínuo: novas tendências para o aumento da produtividade
Dragone, Giuliano;Mussatto, Solange Inês;Silva, Jo?o Batista de Almeida e;
Ciência e Tecnologia de Alimentos , 2007, DOI: 10.1590/S0101-20612007000500007
Abstract: the present work evaluated the ethanol volumetric productivity during fermentation of worts with elevated original extract, for high gravity brewing by continuous process using yeasts immobilized on brewer's spent grain. worts with different original extract (14.3 op, 15.2 op and 19.6 op) were prepared from a wort of 22 op elaborated with malt and high maltose adjunct in an adjunct:malt ratio of 1:2.8. the fermentations were performed in a bubble column reactor, at 15 oc, using a dilution rate of 0.04 h-1 and a constant gas flow of 250 ml/min (200 ml/min co2 and 50 ml/min air). according to the results, the ethanol volumetric productivity increased when the original extract concentration of the wort was increased, the maximum value (2.09 g.l-1.h-1) was attained for the wort with 19.6 op. this value represents an increase of 345% when compared with the productivity (0.47 g.l-1.h-1) of the discontinuous fermentation of worts with 20 op. it was thus concluded that beer production by continuous fermentation of worts with elevated original extract can obtain expressive gains in the ethanol volumetric productivity when compared with the discontinuous process.
Ethnopharmacological versus random plant selection methods for the evaluation of the antimycobacterial activity
Danilo R. Oliveira,Gilda G. Leit?o,Tatiane S. Coelho,Pedro E. Almeida da Silva
Revista Brasileira de Farmacognosia , 2011,
Abstract: The municipality of Oriximiná, Brazil, has 33 quilombola communities in remote areas, endowed with wide experience in the use of medicinal plants. An ethnobotanical survey was carried out in five of these communities. A free-listing method directed for the survey of species locally indicated against Tuberculosis and lung problems was also applied. Data were analyzed by quantitative techniques: saliency index and major use agreement. Thirty four informants related 254 ethnospecies. Among these, 43 were surveyed for possible antimycobacterial activity. As a result of those informations, ten species obtained from the ethnodirected approach (ETHNO) and eighteen species obtained from the random approach (RANDOM) were assayed against Mycobacterium tuberculosis by the microdilution method, using resazurin as an indicator of cell viability. The best results for antimycobacterial activity were obtained of some plants selected by the ethnopharmacological approach (50% ETHNO x 16,7% RANDOM). These results can be even more significant if we consider that the therapeutic success obtained among the quilombola practice is complex, being the use of some plants acting as fortifying agents, depurative, vomitory, purgative and bitter remedy, especially to infectious diseases, of great importance to the communities in the curing or recovering of health as a whole.
Alcohol dependence induced in rats by semivoluntary intermittent intake
Macieira M.S.,Almeida W.G.,Silva E.A.,Schenberg L.C.
Brazilian Journal of Medical and Biological Research , 1997,
Abstract: The objective of the present experiment was to assess ethyl alcohol (ETOH) dependence brought about by a semivoluntary intermittent intake regimen in rats. Male Wistar rats weighing 150-250 g at the onset of the experiment were assigned to the following groups: 0% ETOH (N = 11), 5% ETOH (N = 20), 20% ETOH (N = 20) and 40% ETOH (N = 18). ETOH solutions were offered at the end of the day and overnight from Monday to Friday, and throughout weekends, for 90 days. The concentration of the ETOH solutions was increased in a stepwise fashion allowing the rats to get used to the taste of alcohol. Reposition of pure water was permitted during 1-h water drinking periods in the morning. Daily volume intake (± SEM) averaged 25.4 ± 0.4 ml (0% ETOH), 23.8 ± 0.6 ml (5% ETOH), 17.6 ± 0.7 ml (20% ETOH) and 17.5 ± 0.6 ml (40% ETOH). ETOH consumption differed significantly (P<0.05) among groups, averaging 4.4 ± 0.2 g kg-1 day-1 (5% ETOH), 10.3 ± 0.3 g kg-1 day-1 (20% ETOH) and 26 ± 1.2 g kg-1 day-1 (40% ETOH). Furthermore, ETOH detection in plasma 10-12 h after offering the solution indicated that its consumption in the 40% ETOH group was sufficient to override its metabolism. Overt signs of ETOH dependence, such as increased thirst, hyperactivity, puffing, hair ruffling and startle responsiveness as well as reduced drowsiness, were significantly increased in the 20% and 40% ETOH groups compared to the 0% and 5% groups. Accordingly, the model described here proved to be a useful tool for the evaluation of subtle or moderate behavioral and physical consequences of long-term ETOH intake
Fermions in a warped resolved conifold
D. M. Dantas,J. E. G. Silva,C. A. S. Almeida
Physics , 2013, DOI: 10.1016/j.physletb.2013.07.021
Abstract: We investigated the localization of the spinorial field in a braneworld built as a warped product between a 3-brane and a 2-cycle of the resolved conifold. This scenario provides a geometric flow that controls the singularity at the origin and changes the properties of the fermion in this background. Furthermore, due the cylindrical symmetry according to the 3-brane and a smoothed warp factor, this geometry can be regarded as a near brane correction of the string-like branes. This geometry allows a normalizable and well-defined massless mode whose decay and value on the brane depend on the resolution parameter. For the Kaluza-Klein modes, resolution parameter also controls the height of the barrier of the volcano potential.
Page 1 /494632
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.