ABSTRACT Copper is an essential element for beet; however, it needs to be made available in adequate quantities since this nutrient, which is a heavy metal, can cause toxicity to plants and/or humans. This study aimed to evaluate the agronomic performance of beet fertigated with copper in a semi-arid region of Brazil. Two experiments were carried out in complete randomized blocks, with five treatments (0, 1.5, 3.0, 4.0, and 6.0 kg ha-1 of copper) and four replicates. In 2019, the copper content was within the adequate range for beet. In 2021, fertigation with copper above 0.8 kg ha-1 led to contents in the phytotoxicity range, which may explain the reduction in total and tuberous root dry mass accumulation. Fertilization with copper increased marketable yield in 2019 (17.32 t ha-1 at the dose of 3.9 kg ha-1 of copper), while, in 2021, there was no fit of the equations. Copper fertilization altered the tuberous root pH but did not influence the other tuberous root quality components. Plants fertilized with copper accumulated more copper in the leaves than in the tuberous root, with a maximum accumulation of 6.0 kg ha-1 of copper in 2019 and 2021. Fertilization with 3.9 kg ha-1 suits soils with low copper content.

RESUMO O cobre é um elemento essencial à beterraba, no entanto, é necessário disponibilizá-lo em quantidade adequada uma vez que esse nutriente, que é um metal pesado, pode causar toxicidade às plantas e, ou, ao ser humano. Esta pesquisa teve como objetivo avaliar o desempenho agronômico de beterraba fertirrigada com cobre em uma região semiárida do Brasil. Foram conduzidos dois experimentos em delineados em blocos casualizados ao acaso, com cinco tratamentos (0, 1.5, 3.0, 4.5 e 6.0 kg ha-1 de cobre) e quatro repetições. Em 2019, o teor de cobre estava dentro da faixa adequada para a beterraba. Em 2021, a fertirrigação com cobre acima de 0.8 kg ha-1 proporcionou teores na faixa de fitotoxicidade, o que pode explicar a redução no acúmulo de massa seca total e de raízes tuberosas. A adubação com cobre aumentou a produtividade comercial em 2019 (17.32 t ha-1 na dose de 3.9 kg ha-1 de cobre) enquanto que, em 2021, não houve modelo ajustado. A adubação alterou o pH da raiz tuberosa, mas não influenciou nos demais atributos de qualidade pós-colheita da raiz tuberosa. Plantas adubadas com cobre acumularam mais cobre nas folhas do que na raiz tuberosa, com máxima acumulada em 2019 e em 2021, na dose 6.0 kg ha-1 de cobre. A adubação com 3.9 kg ha-1 é adequada para solos com baixo teor de cobre.

Abstract Ceramics are widely employed as thermal insulating materials for thermal barrier coatings (TBC) due to their low thermal conductivity, chemical stability, and high wear and corrosion resistance at high temperatures. The aim of this work was to study the influence of the CO2 laser beam parameters on the single-step irradiation of pre-placed yttria-stabilized zirconia (YSZ) powders on NiCrAlY/AISI 316L substrates. In order to increase the coating’s lifetime and performance, it is proposed a laser sintering of powder-beds (LSP) technique to obtain homogenous YSZ coatings, with controlled surface microstructures. The obtained coatings were characterized by optical microscopy, field emission scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction (XRD). The laser intensity and interaction time were the main laser parameters used to control the surface temperature and the combination of these parameters were used to establish a process chart. The LSP resulted in controlled smooth coating surfaces and columnar growth with submicrometric grain size. XRD analyses showed the prevalence of non-transformable tetragonal zirconia, which is known to exhibit higher stability and thermal wear resistance.

Objetivou-se, com a realização deste trabalho, obter o ajuste do modelo matemático adaptado de cinética de primeira ordem e os respectivos parâmetros cinéticos para descrição da degradação da matéria orgânica em SACs cultivados com lírio amarelo (Hemerocallis flava), no tratamento de esgoto doméstico. Os SACs foram cultivados com lírio amarelo e submetidos a diferentes taxas de carregamento orgânico superficial (TCOs) de esgoto doméstico: 44; 98; 230 e 395 kg ha-1 d-1 de DBO. O modelo matemático adaptado de decaimento do material orgânico apresentou bom ajuste e descreveu adequadamente a cinética de remoção de matéria orgânica (DQO) nos sistemas avaliados apresentando, geralmente, R² superior a 75%. Em ordem crescente de TCO valores de coeficientes de degradação (Kv) foram, respectivamente, de 0,45; 0,69; 1,23 e 1,72 d-1, considerados baixos para os dois primeiros SACs e normais para os outros dois, e os valores de "n" de 0,448; 0,107; 0,327 e 0,461, na faixa normalmente encontrada na literatura.

This work aimed to obtain the adjustment of the mathematical model adapted from the first order kinetics and its respective parameters for describing the organic matter degradation in constructed wetlands (CWs) planted with yellow lily (Hemerocallis flava) for the treatment of domestic sewage. The CWs were cultivated with yellow lily and subjected to different surface organic loading rates (TCOs) of domestic sewage: 44, 98, 230 and 395 kg ha-1 day-1 BOD. The mathematical model adapted from the decay of organic material showed a good fit and adequately described the kinetics of removal of organic matter (COD) in the evaluated systems, with generally more than 75% R². In ascending order of TCO values of degradation coefficients (Kv) were, respectively, of 0.45, 0.69, 1.23 and 1.72 d-1, considered low for the first two CWs and normal for the other two, and the values of "n" of 0.448, 0.107, 0.327 and 0.461 in the range normally found in the literature.