Propriedades tecnológicas do látex e da borracha natural de clones de Hevea brasiliensis

A indústria da borracha está cada vez mais exigente em relação à qualidade e a uniformidade da borracha natural produzida no Brasil. Neste trabalho as propriedades tecnológicas do látex e da borracha natural dos clones de seringueira GT 1, PB 235, IAN 873 e RRIM 600 [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-.Arg] foram avaliadas pelos ensaios padrões do conteúdo de borracha seca (DRC%), porcentagem de nitrogênio (N%) e porcentagem de cinzas (CNZ%) por dois anos consecutivos; os dados obtidos foram correlacionados com dados de temperatura e precipitação. As propriedades do látex e da borracha natural variaram (P < 0.01) em função do tipo de clone e entre coletas. O DRC% diminuiu no início da estação seca (maio a junho), enquanto N% e CNZ% aumentaram. O período de abril a junho revelou ser crítico, pois os valores da N% oscilaram acima 0,60%, fora dos padrões estabelecidos pela norma técnica brasileira ABNT/NBR. O clone RRIM 600 foi menos suscetível às variações climáticas.Rubber industry has increased the requirements for quality and uniformity of natural rubber produced in Brazil. Technological properties of latex and natural rubber of clones GT 1, PB 235, IAN 873 and RRIM 600 [Hevea brasiliensis (Willd. Former Adr. de Juss.) Muell.- Arg] were evaluated by standard methods of the dry rubber content (DRC%), percentage of nitrogen (N%) and percentage of ashes (ASH%) in two consecutive years; data were correlated with temperature and precipitation. Properties of latex and natural rubber varied (P < 0.01) as a function of clone type and among tappings. DRC decreased in the beginning of the dry season (May to June) and N% and ASH% increased in the same period. April to June was a critical period, when N% was above 0.60%, out of standards established by the technical standard ABNT/NBR in Brazil. Clone RRIM 600 was less susceptible to climatic variations

Evaluation of latex and of raw natural rubber of rubber tree clones recommended for the São Paulo State, Brazil

Este trabalho teve como objetivo avaliar parâmetros do látex e da borracha natural de quatro clones de seringueira [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg.] cultivados em larga escala na Fazenda Cambuhy no Município de Matão, Estado de São Paulo. Foram utilizados látex de 20 árvores do estande de cada um dos clones, GT 1, PB 235, IAN 873 e RRIM 600, com 12 anos de idade, no quarto ano de sangria sob o sistema 1/2S d/3 6d/7. 11m/y. ET 5,0%. Pa 12/y. Foram analisados o conteúdo de borracha seca, porcentagem de cinzas, porcentagem de nitrogênio, plasticidade Wallace (PO), índice de retenção de plasticidade e viscosidade Mooney (VR). O conteúdo de borracha seca apresentou tendência de queda com o decréscimo da temperatura ao longo do ano (r = 0,75). Contrário ao conteúdo de borracha seca, as propriedades porcentagem de nitrogênio e porcentagem de cinzas apresentaram tendência de aumento com a redução da temperatura ao longo do período das coletas. A correlação entre PO e VR foi linear e elevada (r = 0,93). Os altos valores de PO e VR indicam que as borrachas dos clones estudados são consideradas como borrachas duras. Os valores do índice de retenção de plasticidade foram baixos, indicando baixa resistência à degradação térmica. Os resultados mostram influência marcante dos fatores climáticos em algumas propriedades dos látices e da borracha natural dos clones estudados, sugerindo condição importante para se entender o comportamento dos mesmos.The objective of the present paper was to evaluate the parameters of latex and natural rubber from four clones of rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg.] planted in large scale in Cambuhy plantations in São Paulo State, Brazil. Latex from 20 trees of each 12-year-old clones viz. GT 1, PB 235, IAN 873 and RRIM 600 following the 1/2S d/3 6d/7. 11m/y. ET 5.0%. Pa 12/y tapping system in the fourth year of yielding. The studied parameters were percentages of dry rubber content (DRC), ashes and nitrogen, Wallace plasticity (PO), plasticity retention index (PRI) and Mooney viscosity (VR). Results indicated a trend of reduction in DRC with decreasing temperatures (r = 0.75). Results of ashes percentages and N percentages indicated a behavior opposite to DRC, increasing with the decreasing temperature along the year. A high correlation value (r = 0.93) was obtained between PO and VR. The high values obtained for PO and VR indicate that the rubber studied should be considered as hard rubbers. The PRI values for these clones were considered low and are associated with a low resistance to thermal degradation. The results obtained indicate a strong influence of climatic conditions on some properties of the lattices and natural rubber for the studied clones. Such parameters suggest an important condition to understand the behavior of these clones

Coupled ElectromagneticThermal Simulation of a Power Transformer by 3D FEM

Power transformers are the most common equipment in an electric power system, which has been manufactured in the last decade. However, overheating can damage them, considerably reducing their operation lives, which may cause economic losses to the power utilities. The motivation of this paper is to investigate the time and power overload limits that a power transformer can be subjected to and how it will impact its temperature. Investments in the grid can be delayed if a transformer can support some overload during some momentary load demand increase. In this context, this paper presents a study of a 30/40MVA power transformer by 3D finite element method (FEM) for coupled thermal-electromagnetic simulations to investigate its thermal behaviour when it is submitted to its nominal load at a steady-state operation and a variable load during a period of one day. The simulations were performed with the commercial software packages Flux 3D and AcuSolve, for electromagnetic and thermal modelling, respectively. The modelled equipment was based on a power transformer installed in the Light Serviços de Eletricidade S.A, the utility that supplies electrical energy to the city of Rio de Janeiro, in Brazil. Since the literature doesn’t present many works simulating coupled thermal-electromagnetic power transformers in 3D-FEM, this paper has the goal to bring new contributions to this field. Three study cases were modelled, and some simplifications in transformer’s geometry were made in some of them to reduce the computation time usually required for such a simulation. The obtained results are presented and compared with the measured values for the temperature in the hot spot of the transformer and in the top of the oil, to investigate the impact of these simplifications in the calculated results

Effect of rootstock on the scion of Hevea brasiliensis through metabolic analysis of latex samples by 1H NMR

In this study, the effect of rootstock on grafting through metabolomic analysis of latex (Hevea brasiliensis) samples was verified by 1H nuclear magnetic resonance (NMR) and multivariate data analysis. Sixteen metabolites present in the latex cytosol were characterized by NMR. PCA analysis showed that the latex samples of the RR and GR groups can be differentiated. The GR group samples present a metabolic profile similar to the RR group samples, while the RG group is in an intermediate position between RR and GG groups. Sucrose and formate contributed greatly to the separation obtained by PCA, presenting a good correlation between the results. 1H NMR was an efficient technique to differentiate latex samples from different types of rootstocks and grafting and in the future could be used to predict rubber production by latex analysis

PERCEPTIONS OF PUERPERAS REGARDING THE BENEFITS OF BREASTFEEDING IN THE FIRST HOUR FOLLOWING BIRTH

El amamantamiento precoz es una estrategia para la promoción al amamantamiento materno en Brasil, pero pocos estudios evalúan la aplicación de esa práctica del punto de vista de las madres. Con un abordaje cualitativo, fueron investigadas las percepciones de puérperas sobre el amamantamiento en la primera hora posparto. Los datos fueron recogidos por la observación de los principios éticos y los relatos fueron clasificados en las categorías: Lo qué es la leche materna; Beneficios del amamantamiento precoz para madre e hijo; yOrientaciones y práctica del amamantamiento precoz. A pesar de reconocerse la leche materna como alimento adecuado para el desarrollo del bebé, las puérperas tenían solamente informaciones generales acerca del amamantamiento materno y la mayoría desconocía la teoría y práctica del amamantamiento precoz. Los resultados apuntan la necesidad de concientizar a las gestantes sobre la importancia del amamantamiento precoz durante el acompañamiento prenatal.Early breastfeeding is a strategy for promoting breastfeeding in Brazil, but few studies have evaluated the application of this practice from the point of view of the mothers. The puerperas’ perceptions regarding breastfeeding in the first hour following birth were investigated, using a qualitative approach. The data were collected observing ethical principles and the reports were classified in the following categories: What is breast milk?; The benefits of early breastfeeding for mother and child; and, guidance and practice of early breastfeeding. Although they recognize breast milk as an appropriate food for the baby’s development, the puerperas have only general information about breastfeeding, and the majority are unaware of the theory and practice of early breastfeeding. The findings indicate the need to raise pregnant women’s awareness regarding the importance of early breastfeeding during the prenatal monitoring.A amamentação precoce é uma estratégia para a promoção ao aleitamento materno no Brasil, mas poucos estudos avaliam a aplicação dessa prática do ponto de vista das mães. Em uma abordagem qualitativa, investigaram-se as percepções de puérperas sobre a amamentação na primeira hora pós-parto. Os dados foram coletados pela observação dos princípios éticos e os relatos foram classificados nas categorias: O que é o leite materno; Benefícios da amamentação precoce para mãe e filho; eOrientações e prática da amamentação precoce.Embora reconhecessem o leite materno como alimento adequado para o desenvolvimento do bebê, as puérperas possuíam apenas informações gerais sobre aleitamento materno e a maioria desconhecia a teoria e a prática da amamentação precoce. Os achados apontam a necessidade de se conscientizar as gestantes sobre a importância da amamentação precoce durante o acompanhamento pré-natal

Detecting spatiotemporal variability in the physicochemical properties of water in the Lower Mearim using remote sensing data

Natural or anthropogenic chemical compounds of different origins often accumulate in estuarine regions. These compounds may alter the water quality. Therefore, It is important to constantly monitor the quality of estuarine regions. A combination of remote sensing and traditional sampling can lead to a better monitoring program for water quality parameters. The objective of this work is to assess the spatiotemporal variability of the physicochemical properties of water in the lower region of the Mearim River and estimate water quality parameters via remote sensing. Samples were collected at 16 points, from Baixo Arari to the mouth of the watershed, using a multiparameter meter and Landsat 8 satellite images. The physicochemical parameters of the water had high salinity levels, between 2.30 and 20.10 parts per trillion; a high total dissolved solids content, between 2.77 and 19.70 g/L; and minimum dissolved oxygen values. Estimating the physicochemical properties of the water via remote sensing proved feasible, particularly in the dry season when there is less cloud cover

Biomassa, trocas gasosas e aspectos nutricionais de plantas jovens de pau de balsa (Ochroma pyramidale (Cav. Ex Lamb.) Urb.) submetidas à fertilização fosfatada em ambientes contrastantes de irradiância

The irradiance and nutrient supply affect the assimilation of carbon and influence the gain and biomass partition. The aim of this research was to investigate the growth and photosynthesis in young plants of Ochroma pyramidale subjected to contrasting light environments and phosphorus fertilization. Young plants of O. pyramidale were exposed to two irradiance levels (Low: 10 to 15 and High: 1200 to 1400 μmol m-2 s-1) and two levels of P fertilization (0 and 1 mM as KH2 PO4) for 160 days. The experimental design was a completely randomized in factorial arrangement (2 x 2), with 10 replications. The greatest growth in height and diameter was observed in plants fertilized with phosphorus and under high irradiance. Concerning the allocation of dry mass, plants under high irradiance invested more in root mass ratio and plants under low irradiance in leaf mass ratio. For foliar P content, the plants fertilized with P exhibited values 137 and 54% higher than the plants not fertilized with P, under high and low irradiance, respectively. The absence of P fertilization promoted intense reduction in the efficiency of electron transport, as demonstrated by the values of photochemical efficiency of photosystem II, and photosynthetic rates. The greatest biomass production and higher photosynthetic rates in plants fertilized with phosphorus and under higher irradiance suggest that O. pyramidale plants have appropriate functional mechanisms to show a better growth and physiological performance in open fields (high irradiance), common in forest plantations or environments in recovery process

Relatório de Primavera 2022

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