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An experiment was carried out during four harvests (two in the cold season and two in spring) with the objective of determining the N losses by leaching and volatilization as well as their dynamics in a Brown Grayish soil in the Central Cuban region at the Experimental Station of Soil "Escambray" in corn crop. Six N levels were applied (0, 60, 120, 180, 240 y 300 kg ha-1 of N) a third of which with ammonium sulfate when planting and the remaining 35 days with urea. Volatilization of ammonium in form of ammonia was determined using Nömmik's method in levels 0, 120 and 240 kg ha-1 to 3, 7, 14, 21, 28 and 35 days after fertilization. The washing of NO3- and NH4+ was quantified using a lysimeter type Ebermeyer. Ammonia losses due to volatilization increased along with N doses in the two seasons, reaching its maximum level between the 3rd and 7th days after the second urea fertilization with values of 25 kg ha-1. NH4+ leaching was insignificant. while NO3- losses increased along with the doses and were approximately 13 % of the applied N reaching values of 47 kg ha-1 in the dose of 300 kg ha-1. It is concluded that in Brown Grayish soil the greatest losses due to ammonium volatilization occur with urea and the greatest leaching occurs in NO3-. [ABSTRACT FROM AUTHOR]

Corn (Zea mays L.) is the second most cultivated cereal in the world and is used as raw material for different kind of industries. To date no reports about obtaining giberellic acid (GA3 ) from corn have been found. In the present study two methods for extracting solid samples were evaluated: lixiviation and dynamic sonication-assisted solvent extraction (DSASE), for obtaining giberellic acid from corn germinated seeds. In lixiviation, the physical method (agitation and sonication), solvent, and time were the parameters analyzed; while in DSASE the variables were: solvent, flow, and time. The most efficient technique was DSASE employing acetonitrile-formic acid 5% (80:20, v:v) as solvent at a flow o f 0,4 mL/ min for 25,0 min, obtaining a concentration o f 30,012 mg/kg giberellic acid. Identification and quantification were performed by high performance liquid chromatography (HPLC) with diode array detector (DAD). These results showed that dynamic sonication-assisted solvent extraction (DSASE) is a novel and powerful alternative technique for obtaining giberellic acid, because o f its high efficiency; low solvent consumption and simplicity in obtaining the extract. [ABSTRACT FROM AUTHOR]

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In the present investigation, a process of extraction and stabilization of the anthocyanines, the natural dye in jambolan fruit (Syzygium cumini (L). Skeels) was developed to be used in the manufacture of a shampoo as a substitute for artificial colorants. Initially jambolan fruits were collected, frozen, lyophilized, and cold macerated using a solvent mixture: (95% ethanol:0.1 N hydrochloric acid 85:15). 20% of dye was extracted and its concentration was 1,865 ppm and its total monomeric anthocyanin was 43mg cy-3-gly/100 g fresh weight. Then, the accelerated stability of the extracts was evaluated at 33 °C and 50 °C and pH=3 and pH=4, of both the natural colorant and Red No. 40. The anthocyanin were more stable at pH=3 than at pH=4 and at 33° C than at 50 °C and at the latter temperature red 40 is more stable. Subsequently, a shampoo with the addition of the extracted dye was developed, showing that it can be used as a substitute for artificial colorant. Finally, the finished product was characterized by physicochemical tests, according to COVENIN standards. [ABSTRACT FROM AUTHOR]

Copyright of Avances en Ciencias e Ingeniería is the property of Avances en Ciencias e Ingenieria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Colombiana de Biotecnología is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In a previous article began the study that continues in this, where it will be considered the effect of factors such as: time, flow of SO2 and relation Aire-SO2 on the lixiviation of the Ni, Co, Cu, Zn, Mn and Mg with preference to the Fe contained in the marine nodules. During the experiences, fixed values were assigned to the factors: temperature, relation solid-liquid, degree of agitation, pH and distribution of size of the solid particles. The statistical examination of the results indicates between other things the following: - The relation air-SO2 is the factor that lowest causes the biggest effect on the extraction of the Ni, and it makes it in its lowest level. - The lixiviation of Co is not affected by any of the factors in the experimental environment. - According to the studied experimental factors, the relation air-SO2 is the one that presented the biggest effect in almost all the cases, the sense of its effect is always the same one, except in the case of the Cu whose extraction favors with its highest level; - The selective lixiviation of the Ni and Co with relation to the Fe indicates that the convenient level for the relation air-SO2 is the highest of the one used in the experiments, contrary to the one detected when the lixiviation of the elements is analyzed separately, without assisting to its selectivity with relation to the Fe. [ABSTRACT FROM AUTHOR]