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Search Results: 1 - 10 of 468298 matches for " A.A. Ramos "
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Aplica??o de herbicidas pós-emergentes via irriga??o por aspers?o: revis?o
Vieira, R.F.;Silva, A.A.;Ramos, M.M.;
Planta Daninha , 2003, DOI: 10.1590/S0100-83582003000300019
Abstract: although herbigation (application of herbicides by irrigation) has increased in brazil, the research results evaluating this technique are scarce and mostly unknown, especially when herbigation involves the use of postemergence (post) herbicides. the objective of this review was to discuss the main articles related to post herbicides applied through overhead sprinkler irrigation in most of the studies revised a simulated sprinkler system was used and the herbicide rates applied through herbigation were the same used through conventional application (spraying). the amount of water used to apply a given herbicide varied from 1 to 14 mm (10,000 to 140,000 l ha1). the most studied herbicides which were effective when applied through herbigation are: bromoxynil, acifluorfen, fomesafen, lactofen and the aryloxyphenoxypropionate herbicides. the herbicides atrazine, chlorsulfuron, dicamba, sethoxydim, and triasulfuron, included in, at least, one study, showed potential for weed control through herbigation. these herbicides have, at least, two of the following properties: low water solubility, quick leaf absorption, and root absorption. variation in the volume of water for herbigation had little or no effect on herbicide weed control effectiveness. in general, mixing a non-emulsified oil with the herbicide before the injection into irrigation water may increase deposition and retention of herbicides on the leaf surface. other factors that can affect herbicide effectiveness applied via herbigation are water quality and application timing. generally, the following herbicides are not weed control effective in herbigation: bentazon, glyphosate, and paraquat, since they have high solubility in water, being slowly absorbed by foliage and/or not absorbed by the roots.
J.W. Navalta,B.K. McFarlin,T.S. Lyons,A.A. Ramos
Biology of Sport , 2011,
Abstract: Exercise-induced lymphocyte apoptosis has been reported using biochemical analysis and morphological assessment. Morphological evaluation is limited by the subjective nature of the technique. This investigation evaluated the intra- and interrater reliability of trained and untrained observers assessing apoptosis morphologically. Blood smears at baseline (PRE) and following cycle ergometer exercise (POST) were assessed microscopically for each condition. To obtain reliability measures, cell sets were evaluated for morphological characteristics of apoptosis on two separate occasions by trained and untrained observers using the intraclass correlation coefficient. Test-retest reliability for trained observers was higher for both conditions than untrained observers. Interrater reliability was below-average or below acceptable regardless of training status. Exercise may induce apoptotic changes in lymphocytes that are more easily discriminated by trained observers. Investigations assessing exercise-induced apoptosis should train observers in order to produce reliable results, and a single trained observer would be expected to yield the most reliable results.
Effects of Steel Fibers and Iron Filings on Thermal and Mechanical Properties of Concrete for Energy Storage Application  [PDF]
A.A. Adeyanju, K. Manohar
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2011, DOI: 10.4236/jmmce.2011.1015111
Abstract: An experimental study on the thermal properties of iron filings and steel-fiber-reinforced concrete for solar/thermal energy storage application is presented in this report. It takes into account the results of measurements of thermal conductivity, thermal resistivity, thermal diffusivity and the results of compressive strength, density as well as energy storage capacity calculated from the knowledge of the above measured parameters. The experimental testing method is described as well: based upon the linear heat source theory, it requires the use of a special probe to be inserted into the sample. The experimentation was forwarded to test concrete aggregate mixtures with three different sizes and same quantity of steel fibers; two different quantities of iron filings and one plain concrete. The measurements were carried out from the pouring time of cubic samples and were ended up when hardened conditions were achieved. The results indicate that the steel fibers and iron filings have influence on the thermal and mechanical properties of the concretes tested, thus the iron filings and steel fibers reinforced concrete is suitable for better solar/thermal energy storage due to an increase in storage capacity over plain concrete.
Fecunda o in vitro com sêmen de bovinos da ra a Gir
Ramos A.A.,Camargo L.S.A.,Sá W.F,Ferreira A.M.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2000,
Abstract: Estudaram-se os efeitos da concentra o espermática e do tempo de incuba o do sêmen com ovócitos, durante a fecunda o in vitro, sobre as taxas de penetra o espermática, de fecunda o monoespermática e de clivagem, utilizando-se sêmen de touros da ra a Gir. Ovócitos (n=817) maturados in vitro foram distribuídos em tratamentos visando à fecunda o in vitro (FIV), em um delineamento fatorial 2×2×2, com duas concentra es espermáticas (2 e 4×10(6) espermatozóides/ml), dois períodos de incuba o (12 e 18h) e dois touros (A e B). Espermatozóides viáveis foram obtidos pela técnica de swin-up. A FIV foi realizada em meio fert-talp com heparina, em incubadora com 5% de CO2 em ar atmosférico e 95% de umidade, a 39oC. Após insemina o, 359 ovócitos foram fixados e corados para determina o das taxa de penetra o e poliespermia. O restante foi co-cultivado com células da tuba uterina e TCM-199 por 72h, avaliando-se a clivagem. As taxas de penetra o, fecunda o monoespermática e clivagem n o foram influenciadas (P>0,05) pela concentra o espermática e pelo período de incuba o. O touro B produziu maiores taxas (P<0,05) de penetra o e de clivagem (83,3 e 81,0%, respectivamente) do que o touro A (66,5 e 64,0%). Houve tendência do touro B apresentar maior taxa de polispermia (P=0,067) do que o touro A (16,4 e 6,2 %, respectivamente). As intera es entre tratamentos n o foram significativas (P>0,05). O efeito touro sobre a capacidade de fecunda o dos espermatozóides deve ser considerado quando da fecunda o in vitro.
Lixivia??o de herbicidas no solo aplicados com água de irriga??o em plantio direto
Fontes, J.R.A.;Silva, A.A.;Vieira, R.F.;Ramos, M.M.;
Planta Daninha , 2004, DOI: 10.1590/S0100-83582004000400018
Abstract: the aim of this study was to evaluate the leaching of the herbicides metolachlor and fomesafen in an alfisol soil trough irrigation water under no-till and conventional tillage systems. one experiment consisted of three replications with metolachlor (2,4 kg ha-1) applied in pre-emergence, at water depths of 5, 10 and 15 mm, and fomesafen (0,225 kg ha1) applied in post-emergence, at water depths of 3, 6 and 9 mm. the herbicides had also been applied by spraying. bioassays were carried out under greenhouse conditions using soil samples from the plots. the soil samples were taken each fifteen days from layers of 05, 5-10 and 10-15 cm depth. the first sample, out of a total of four, was collected 15 days after herbicides aplication. the samples were sowed with sorghum bicolor, hybrid br 304, which was used as test-plant. fifteen days after sowing, the whole plants (shoot and roots) were collected for dry mass weight. under no-till, metolachlor was not detected in the soil at 15 days after aplication, regardless of the application method. under the conventional system, only metolachlor herbigation affected sorghum growth at the 0-5 cm soil layer. fomesafen was leached down to 10 cm depth, being detected at the last sampling date (60 days after application), regardless of the application methods. herbigation of metolachlor and fomesafen showed to be reliable in relation to soil movement.
Metolachlor e fomesafen aplicados via irriga??o por aspers?o em plantio direto e convencional
Fontes, J.R.A.;Silva, A.A.;Vieira, R.F.;Ramos, M.M.;
Planta Daninha , 2006, DOI: 10.1590/S0100-83582006000100013
Abstract: the aim of this study was to evaluate the efficacy of metolachlor (2.4 kg a.i. ha-1) and fomesafen (0.225 kg a.i. ha-1) applied via a center pivot on weed control in the common bean plant (phaseolus vulgaris). the cultivar pérola was sown in july (winter). metolachlor was applied with water volume of 5, 10, and 15 mm, and fomesafen with 3, 6, and 9 mm. the herbicides were also sprayed. two checks were included: with and without weeds. the predominant weed in the no-till system was bidens pilosa and in the conventional tillage, artemisia verlotorum. in general, herbigation was more efficient than spray for weed control, regardless of the type of tillage system. water volume of 5 or 10 mm for metolachlor, and 3 or 6 mm for fomesafen, yielded the best results, overall.
Parturition intervals and distributions of parturitions by months of buffalo in Southern and South-eastern Brazil
W.R. Lamberson,A.A. Ramos,C.H.M. Malhado,A.M. Jorge
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2007.s2.593
Abstract: Reproductive rate is an important component of economic success in livestock production. Parturition interval (IEP) is a direct measure of the productivity of the animal. Long IEP reduce the number of calves produced per year. The objective this study was to determine the distribution of parturitions across month and to evaluate factors affecting IEP. The data included 7,588 parturitions of Murrah, Mediterranean and Carabobo buffalo from 10 herds in Southern and South-eastern Brazil. The analysis of distribution of parturitions evaluated the effects of month, year and their interaction on birth date of calves by using a Chi-Square test in SAS PROC FREQ (SAS Institute, Cary, NC, USA). Parturition intervals (n = 2,630) were evaluated using analysis of variance in SAS PROC GLM. The model for IEP included the fixed effects of season (December to May = 1, June to November = 2), year, season x year, sex of the preceding parturition, age of weaning of the previous calf, and herd. All sources of variation were significant (P<0.0001) except sex of the preceding parturition (P <0.85). The mean IEP was 446.7 ± 10.4 days, for seasons 1 and 2 IEP were 419.8 ± 11.3 and 473.6 ± 40.7 days, respectively, a difference of 54 days. As weaning age increased there was a lengthening of IEP. Buffalo in Brazil showed seasonal parturition with calving concentrated from January to April, although the frequency by month differed across years (P<0.0001). These months also had the lowest calving interval.
Evaluation of water beef buffalo from birth to two years using different growth curves
A.A. Ramos,J.C. DeSouza,C.H.M. Malhado,A.M. Jorge
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2007.s2.318
Abstract: The buffalo is a domestic animal species of growing world-wide importance. Research to improve genetic improvement programs is important to maintain the productivity of buffalo. The objective this research was to evaluate the growth of Brazilian buffalo to two years of age with different growth curves. Growth curves consolidate the information contained in the weight-age data into three or four biologically meaningful parameters. The data included 31,452 weights at birth and 120, 205, 365, 550 and 730 days of buffalo (n = 5,178) raised on pasture without supplementation. Logistic, Gompertz, quadratic logarithmic, and linear hyperbolic curves (designated L, G, QL, and LH, respectively) were fitted to the data by using proc NLIN of SAS (SAS Institute, Inc., Cary, NC, USA). The parameters estimates for L [WT= A * (((1 + exp (-k * AGE)))**-m)] were A = 865.1 ± 5.42; k= 0.0028 ± 0.00002; M= 3.808 ± 0.007; R2 = 0.95. For G [WT= A * exp (-b * exp (-k * age)] the parameters estimates were A= 967.6 ± 7.23; k = 0.00217 ± 0.000015; b = -2.8152 ± 0.00532. For QL [WT= A + b*age + k*(age*age) + m*log (age)] parameters estimates were A= 37.41 ± 0.48; k= 0.00019 ± 6.4E-6; b= 0.539 ± 0.006; m= 2.32 ± 0.23; R2=0.96. For LH [WT= A + b*AGE + k*(1/AGE)] the parameters estimates were A= 23.15 ± 0.44; k=15.16 ± 0.66; b= 0.707 ± 0.001; R2= 0.96. Each of these curves fit these data equally well and could be used for characterizing growth to two years in beef buffalo.
Evaluation of development traits of beef buffalo in Brazil using multivariate analysis
J.C. DeSouza,A.A. Ramos,C.H.M. Malhado,A.M. Jorge
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2007.s2.321
Abstract: The buffalo population in Brazil increased about 12.9% between 1998 and 2003, to 2.8 million head, evidencing the importance of this species for the country. The objective this work was evaluation of animal growth using multivariate analysis. The data were from 2,944 water buffalo from 10 herds raised in pasture conditions in Brazil. Principal components and genetic distances were estimated using proc PRINCOMP and proc CANDISC in SAS (SAS Inst. Inc. Cary, NC, USA). Variables analyzed were birth weight (BW), age at weaning (AW), weaning weight (WT), weight adjusted to 205 d (W205), total gain between BW and WT (TG), daily gain between BW and WT (DG), weight adjusted to 365 d (W365), total gain between WT and W365 (TG3), daily gain between WT and W365 (TGD3), weight adjusted to 550 d (W550) and weight adjusted to 730 d (W730). Means and standard deviations for each variable were 39.4 ± 3.2 kg, 225.6 ± 38.8 d, 209.4 ± 39.4 kg, 195.4 ± 30.2 kg, 157.4 ± 32.0 kg, 0.77 ± 0.16 kg/d, 282.0 ± 43.5 kg, 73.9 ± 33.9 kg, 0.53 ± 0.21 kg/d, 406.8 ± 67.9 kg, and 468.2 ± 70.6 kg, respectively. The eigenvalues to four first principal components were 5.29, 2.54, 1.66, 1.01, and justify 48%, 23%, 15% and 9%, respectively, with a total cumulative 95%. We created an index using the first principal component which is Y= 0.0552 BW + 0.0438 AW + 0.3142 WT + 0.3549 W205 + 0.3426 TG + 0.3426 DG + 0.4070 W365- 0.1531 TG3 - 0.2059 TGD3 - 0.3833 W550 - 0.3966 W730. This index accounted for 48% the variation in the correlation matrix. This principal component emphasizes early growth of the animal. Estimates the pair-wise squared distances between herds, D2(i|j)= (xi-xj)’ cov-1(xi-xj), using with basis the average of weight of animals, showed the largest distance between herds eight (Murrah: DF) and seven (Murrah: Amazon) and the closest distance between herds one (Mediterranean - RS) and five (Jafarabadi - SP).
Brazilian Journal of Chemical Engineering , 1997,
Abstract: - In this work, we applied an experimental planning methodology in order to correlate the necessary amounts with the description of the a tungsten extraction process by microemulsions. The result is a mathematical modelling carried out using the Sheffe Net method, where the mixtures concentration values are represented inside an equilateral triangle. The tungsten concentration process occurs in two stages: extraction and reextraction. The extraction stage was determined by monitoring: phase relative volume (Vr), extraction percentage (%E) and tungsten concentration in the microemulsion phase (Ctm e). The reextraction phase was determined by monitoring: reextraction percentage (%Re) and tungsten concentration in the aqueous phase (Ctaq). Finally, we obtained equations that relate the extraction / reextraction properties to the composition of specific points inside the extraction region, obeying the error limits specified for the acceptance of each parameter. The results were evaluated through the construction of isoresponse diagrams and correlation graphics between experimental values and those obtained through use of equations.
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