SUMMARY Prosopis alba has high potential as forest material and important forage features for arid and semi-arid areas. Prosopis alba is commercially propagated by seeds, because of its rooting difficulties. Its cloning would allow to cultivate highly productive silvicultural materials in less time. The aim of this work was to analyze the lignification degree of P. alba cuttings and mini-cuttings and its relation with the rooting capability. The sprouts obtained from the garden and clonal mini-garden were rooted with different concentrations of IBA. Serial transversal sections of the sprouts were carried out before rooting induction and 40 days after this process to observe the lignification of these material and to relate them with rooted cuttings and mini-cuttings. Results show that mini-cuttings with greater juvenility and etiolation degree presented lower lignification degree and reached higher rooting percentages (99.6%) with respect to cuttings (7.6%). Mini-cutting and etiolation techniques are promising for the vegetative propagation of P. alba and other native species with difficult rooting.

RESUMEN Prosopis alba posee potencial para la producción forestal y forrajera, destacándose su utilización en zonas áridas y semi-áridas. La especie, considerada de difícil enraizamiento, se propaga comercialmente mediante semillas. Su clonación permitiría cultivar materiales de interés silvícola altamente productivos y en un menor tiempo. El objetivo de este trabajo fue analizar el grado de lignificación de estacas y miniestacas de P. alba y su relación con su capacidad de enraizamiento. Los brotes obtenidos del jardín y minijardín clonal fueron inducidos al enraizamiento con diferentes concentraciones de IBA. Se realizaron cortes anatómicos de los brotes, previo a la inducción del enraizamiento y 40 días posteriores al mismo para observar la lignificación de estos materiales y relacionarlos con estacas y miniestacas enraizadas. Las miniestacas con mayor grado de juvenilidad y de etiolación presentaron menor grado de lignificación y lograron mayores porcentajes de enraizamiento (99,6%) con respecto a las estacas (7,6%). Se observó que la utilización de la técnica de miniestacas asociada a la de etiolación son promisoras para la propagación vegetativa de P. alba y posiblemente de otras especies nativas de difícil enraizamiento.

Resumo: O objetivo deste trabalho foi avaliar o efeito do uso de diferentes adubos nitrogenados nas perdas de N por volatilização de NH3 e no rendimento de grãos de cultura de milho (Zea mays) na região semiárida do estado de Sergipe. O milho foi manejado sob condições de sequeiro e preparo convencional. Os tratamentos de fertilização foram: ureia revestida com enxofre (SU) e ureia organomineral (OMU). Também foram incluídos ureia comercial e sulfato de amônio (SA) como referência de fontes de N com alto e baixo potencial de volatilização de NH3, além de um controle não fertilizado com N. As fontes de N foram aplicadas na superfície do solo a uma taxa de 150 kg ha-1 de N, como cobertura, no estádio V5 de crescimento do milho. O experimento foi realizado em 2015 e repetido em 2016. As perdas de N pela volatilização de NH3 foram diferentes entre as fontes de N nos dois anos de estudo, com SA tendo apresentado a menor perda de N e ureia comercial, a maior. Na área tratada com OMU, as perdas pela volatilização de NH3 foram controladas de forma consistente, tendo mostrado redução de 74 e 67% em relação à da ureia regular em ambos os anos. SU, no entanto, apenas mitigou as perdas de NH3 em 2015, tendo as aumentado em 2016, em comparação à ureia comercial. O rendimento de grãos e o status de N da planta de milho, avaliados pela folha-índice, não refletiram claramente a perda de N pela volatilização de NH3. Para o semiárido de Sergipe, OMU é o melhor fertilizante à base de ureia para mitigar as perdas de N pela volatilização de NH3, e o uso de SA é uma alternativa para aumentar o rendimento do milho e eliminar as perdas de N como NH3.

Abstract: The objective of this work was to evaluate the effect of the use of different nitrogen fertilizers on N losses by NH3 volatilization and on the grain yield of a corn (Zea mays) crop grown in the semiarid region of the state of Sergipe, Brazil. Corn was managed under rainfed conditions and conventional tillage. The fertilization treatments were: sulfur-coated urea (SU) and organo-mineral-coated urea (OMU). Regular urea and ammonium sulfate (AS) were also included as a reference of N sources of high and low NH3-volatilization potential, as well as a control without N fertilization. The N sources were applied to the soil surface at a rate of 150 kg ha-1 N as side-dressing at the V5 growth stage of corn. The experiment was carried out in 2015 and repeated in 2016. Losses of N through NH3 volatilization differed among the N sources in the two study years, with AS presenting the lowest N losses and regular urea, the highest. In the area treated with OMU, losses by NH3 volatilization were consistently controlled, showing a reduction of 74 and 67% in relation to that of regular urea in both years. SU, however, only mitigated NH3-N losses in 2015, increasing them in 2016, compared with regular urea. Corn plant grain yield and N status, assessed by the index leaf, did not clearly reflect N losses by NH3 volatilization. For the semiarid of Sergipe, OMU is the best urea-based fertilizer to mitigate N losses by NH3 volatilization, and the use of AS is an alternative to increase corn yield and eliminate N losses as NH3.

Cubic equations of state combined with excess Gibbs energy predictive models (like UNIFAC) and equations of state based on applied statistical mechanics are among the main alternatives for phase equilibria prediction involving polar substances in wide temperature and pressure ranges. In this work, the predictive performances of the PC-SAFT with association contribution and Peng-Robinson (PR) combined with UNIFAC (Do) through mixing rules are compared. Binary and multi-component systems involving polar and non-polar substances were analyzed. Results were also compared to experimental data available in the literature. Results show a similar predictive performance for PC-SAFT with association and cubic equations combined with UNIFAC (Do) through mixing rules. Although PC-SAFT with association requires less parameters, it is more complex and requires more computation time.

The objective of this paper is to quantify the uncertainty of hearing protector attenuation measurements and present the metrology study necessary for the accreditation of the Industrial Noise Laboratory (LARI) at The Federal University of Santa Catarina and Individual Protection Equipment laboratory (LAEPI) of NR consultancy Ltda. - Brazil for hearing protector noise attenuation procedures using the "Real Ear Attenuation at Threshold - REAT" method of the Brazilian National Institute of Metrology Standardization and Industrial Quality - INMETRO. A model for the calculation of measurement uncertainty was developed based on the document: "Guide to expression of uncertainty in measurement" published by the International Organization for Standardization, first edition, corrected and reprinted in 1995, Geneva, Switzerland. The uncertainty of each source of error was estimated and the overall uncertainty of the hearing protector noise attenuation measurement was calculated for each 1/1 octave band frequency and the results used in the single number (NRRsf - Noise Reduction Rating for subject fit) uncertainty calculation. It was concluded that the largest uncertainty is due to the determination of the subject hearing thresholds.

O objetivo deste trabalho foi avaliar a mutagenicidade e o grau de toxicidade de duas plantas tóxicas, a "mamona" (Ricinus communis) e a "coroa-de-cristo" (Euphorbia milii), utilizando infusões das sementes de mamona e o látex da coroa-de-cristo, em células meristemáticas de Allium cepa. Foram analisados: o índice mitótico (IM), as anomalias do ciclo mitótico (ACM), anomalias interfásicas, (AI) e o total de anomalias (TA). As soluções testes foram preparadas em três concentrações: MT1 - 0,5 g/l, MT2 - 1,0 g/l, MT3 - 2,0 g/l, e MT4 como controle. Da coroa-de-cristo extraiu-se o látex e dissolveu-se em água destilada nas concentrações CT1 -0,5 ml/l, CT2 - 1,0 ml/l, CT3 - 2,0 ml/l, e CT4 controle. Os resultados constataram que somente a mamona aumentou a freqüência de anomalias do ciclo mitótico, assim como, as anomalias interfásicas, demonstrando, dessa forma, uma ação tóxica para o material genético, através do teste de Allium cepa.

The aim of this work was to evaluate the mutagenicity and the degree of toxicity of two toxic plants, "castor bean" (Ricinus communis) and the "crown-of-thorns" (Euphorbia milii), using infusions of the seeds of Ricinus communis and the latex of the Euphorbia milii, in meristematic cells of Allium cepa, which were analyzed: the mitotic index (IM), the interphasics anomalies (AI), the mitotic cycle anomalies (ACM), and the total of anomalies (TA). The solutions tests were prepared in three concentrations: MT1 - 0.5 g/l, MT2 - 1.0 g/l, MT3 -2.0 g/l, and MT4 as control. From the Euphorbia milii the latex was extracted and was diluted in distilled water in concentrations: CT1 - 0.5 ml/l, CT2 - 1.0 ml/l, CT3 - 2.0 ml/l, and CT4 as control. The results evidenced that Ricinus communis increased the frequency of mitotic cycle anomalies, as well, the interphasics anomalies, demonstrating, a toxic action for the genetic material, through the test of Allium cepa.