RESUMO Variações nas condições ambientais, como a disponibilidade luminosa, podem afetar a eficiência de controle dos herbicidas por alterar características biológicas das plantas relacionadas à sensibilidade aos herbicidas. Desse modo, objetivou-se avaliar a influência do cultivo em ambientes com diferentes disponibilidades luminosas e da aplicação isolada ou em mistura de glifosato e carfentrazone-etil, sobre a morfofisiologia e o controle de M. atropurpureum. O delineamento adotado foi o de blocos casualizados, em esquema de parcelas subdivididas com 5 repetições. As parcelas foram constituídas de três níveis de sombreamento (pleno sol, 50 e 70% de sombra) e as subparcelas de dois herbicidas (glifosato e carfentrazone-etil) combinados ou não. As doses de glifosato + carfentrazone-etil utilizadas foram 0+40 g ha-1 de carfentrazone-etil, 1,440+0 g ha-1 de glifosato, 1,080+30 g ha-1 de glifosato + carfentrazone-etil e mais um tratamento sem aplicação de herbicida. Plantas de M. atropurpureum cultivadas sob sombreamento apresentaram maior sensibilidade aos herbicidas, maior área dos folíolos e menor taxa fotossintética em comparação ao seu cultivo em ambiente a pleno sol. Em sombreamento, tanto os herbicidas aplicados isoladamente quanto a mistura são efetivos no controle do M. atropurpureum, o que indica maior susceptibilidade dessa espécie aos herbicidas em ambientes com restrição luminosa. A espécie é tolerante aos dois herbicidas testados, isolados ou em mistura, quando crescida a pleno sol.

ABSTRACT Variations in environmental conditions, such as the availability of light, can affect the efficacy of herbicides because they alter the biological characteristics of plants including those that are related to the plant’s sensitivity to herbicides. Therefore, the objective of the present study was to assess the influence of environments with different light availabilities, and of the application of glyphosate and carfentrazone-ethyl (separately or in combination) on the morphophysiology and control of Macroptilium atropurpureum. An experimental design of randomized blocks with five replicates was used, with treatments arranged in a split-plot design. The plots were composed of three levels of shading (full sunlight, 50% shading, and 70% shading); within each plot there were sub-plots, one for each of the two herbicides (glyphosate and carfentrazone-ethyl), used either separately or in combination. The doses of glyphosate + carfentrazone-ethyl applied in the treatments were 0+40 g ha-1 of carfentrazone-ethyl, 1.440+0 g ha-1 of glyphosate, 1.080+30 g ha-1 of glyphosate + carfentrazone-ethyl, and there was an additional treatment that did not include the application of an herbicide. Plants of M. atropurpureum cultivated under shading exhibited higher sensitivity to the herbicides, greater leaflet area, and lower photosynthetic rates than plants cultivated under full sunlight conditions. Under shading, both herbicides applied separately or in combination were effective in controlling M. atropurpureum, which indicates a greater susceptibility of this species to these herbicides in environments with light restriction. The species was tolerant to the two tested herbicides, used either alone or in combination, when grown under full sunlight conditions.

RESUMO Associada ao uso de irrigação, a adubação com biofertilizante favorece a absorção de nutrientes pelas plantas e as propriedades químicas dos solos, porém tais efeitos são pouco estudados no cultivo de Tithonia diversifolia em regiões semiáridas. Avaliaram-se os efeitos de doses de biofertilizante bovino e da irrigação no acúmulo foliar de nutrientes em plantas de Tithonia diversifolia e nos atributos químicos do solo. O estudo foi conduzido entre 3 de dezembro de 2014 e 28 de novembro de 2015 e distribuído em esquema fatorial 5 x 2, consistindo de cinco doses de biofertilizante bovino (0, 40, 80, 120 e 160 m3 ha-1), combinado com e sem irrigação. O delineamento estatístico do experimento foi em blocos casualizados com três repetições. A irrigação promoveu aumento no acúmulo de N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu e B em folhas de Tithonia diversifolia no primeiro corte; entretanto, a alta concentração de bicarbonato na água de irrigação e a presença de chuvas durante o segundo cultivo aumentaram o acúmulo de Cu nas folhas de Tithonia diversifolia em sequeiro quando comparado às plantas irrigadas. O aumento das doses de biofertilizante contribuiu para o incremento da saturação por base e do teor de matéria orgânica, P e K no solo.

ABSTRACT The fertilization with biofertilizer associated with the use of irrigation favors nutrient uptake by plants and soil chemical properties; however, these effects are little studied in Tithonia diversifolia in semiarid regions. This study evaluated the effect of doses of bovine biofertilizer and irrigation on accumulation of nutrients in the leaves of Tithonia diversifolia plants and on soil chemical attributes. The study was carried out from December 3, 2014 to November 28, 2015, and arranged in a 2 x 5 factorial scheme, consisting of five doses of bovine biofertilizer (0, 40, 80, 120 and 160 m3 ha-1), combined with and without irrigation. The experiment was set in a randomized block design, using three replicates. Irrigation promoted increased accumulation of N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu and B in leaves of Tithonia diversifolia in the first cutting. However, the high bicarbonate concentration in the irrigation water and the occurrence of rainfall during the second crop increased the accumulation of Cu in the leaves of Tithonia diversifolia under rainfed condition, compared with irrigated plants. The increase in biofertilizer doses contributed to the increment of base saturation and the contents of organic matter, P and K in soil.

Phase behavior of didodecyl and dioctadecydimethylammonium bromide (DDAB and DODAB) in water was studied using X-ray techniques, differential scanning calorimetry and deuterium nuclear magnetic resonance measurements. Both surfactants self-assemble into lamellar liquid crystalline, either Lα (fluid) and Lβ (gel), phases. The gel-to-fluid phase transition temperature (Tm) in DDAB lamellae was found to be higher than that observed for its vesicles, due to the formation of a stabilized gel phase. In addition, the lamellar phases formed by both amphiphiles differ in their swelling degree and bilayer thickness. DODAB in water formed rather thin bilayers, if compared with the length of the tails, suggesting effective chain interdigitation. These bilayers also presented higher swelling degree than those formed by the shorter-chain homologue DDAB. We propose that these structural properties are strongly influenced by the electrostatic repulsive forces acting on the system.

<p>This work describes the treatment of dairy industry effluent using catalytic ozonation with Fe²⁺ as its catalyst in a semi-batch process with recycle. A fractional factorial design 24^-1 was used with a reduction percentage of total organic carbon (TOCred) as response. Optimal conditions were obtained by the reaction time of 30 min, ozonator power of 35 W, O₂ flow rate of 0.125 L min^-1, Fe²⁺ concentration of 1.0 g L^-1 and pH 4.0 for a 2 L raw effluent. TOCred of 64.03% represents a decrease in concentration from 473.0 to 170.1 mg L^-1, with an estimate cost of US$ 0.03 L^-1effluent. The treatment performed was not sufficient to discharge it directly on surface water; however, significant reduction of TOCred, among physical and chemical characteristics makes a better product to be proceeded into a biological treatment.</p>