Adequação de engates rápidos de aspersores como conectores de mangueira para distribuição de água em sulcos de irrigação

As a way to reduce water losses in furrow irrigation systems, used in fresh market tomato production, farmers are improperly distributing water into the field using plastic hose. The objective of this work was to study the suitability of using quick coupler sprinkler as hose connectors for water distribution in tomato plantation. The first step of the study was to assess the current hose field operation for tomato growers. Subsequently, four models of quick couplers sprinklers available in the market were tested in laboratory to determine the coefficient of resistance, the equivalent tube length, the head loss curve and the linking efficiency. As result, a structural design for hose connectors was presented using the model of coupling with the best hydraulic performance. Additionally, some technical recommendations on its use in irrigation water distribution are highlighted. Despite the requirement for additional field trials, the proposed system has potential to optimize the water use efficiency, to improve workers ergonomic conditions, and ensure good profitability to the producer.

Variação sazonal da fotossíntese, condutância estomática e potencial da água na folha de laranjeira 'Valência'

Seasonal variation in environmental conditions may influence gas exchange rates as well as water relations in perennial species. This work was carried out to evaluate photosynthetic rates (A), transpiration (E), stomatal conductance (g) and leaf water potential (psi f ) in 'Valencia' orange trees grafted on four different rootstocks. Measurements were made twice a day: from 9h00 to 11h00 a.m. and from 1h00 to 3h00 p.m., during January, March and July. A and g were significantly lower and psif was significantly more negative, in the afternoon. The decrease in A may be related to the reduction in g, due to the increase in the vapor pressure deficit between the air and the leaf (VPDair-leaf ) in the afternoon, when temperatures are higher. In spite of the partial stomatal closure in the afternoon, the values for E were approximately the same as those measured in the morning, due to the increase in the VPDair-leaf . A decrease in A and g could also be noted from January to July, that is, from the hot and humid summer months, to the colder and drier winter ones. It was suggested that the decrease in A and g observed from January through March, may be related to the decrease in plant growth rates, which could have influenced the source-sink relationships, since the climatic conditions for both months were similar. The decrease in A and g showed in July, seems to be related to the decrease in both the night temperature and the growth rate of plants.

Hidrocarbonetos aromáticos policíclicos em margarina, creme vegetal e maionese

Polycyclic aromatic hydrocarbons (PAHs) are a group of compounds that have been the subject of much concern due to their toxic potential. In this study, margarine?s, vegetable cream and mayonnaise available on the Brazilian market were analyzed for pyrene, chrysene, benzo(a)pyrene, benzo(b)fluoranthene and dibenzo(a,h)anthracene. The analytical methodology involved liquid-liquid extraction, clean-up on silica gel column and determination by high performance liquid chromatography using fluorescence detector. Variable levels of contamination were found within differents brands of the same product and within differents batches of the same brand. The total PAH content was in the range of 4.1 to 7.1mug/kg in vegetable cream, 1.7 to 3.9mug/kg in margarine and 1.0 to 21.7mug/kg in mayonnaise. In general the products which according to the label contain corn oil showed the highest levels of contamination. Based on these results and on the importance of fat, oils and derived products for the intake of PAHs, it is recommended that producers of margarine, vegetable creams and mayonnaise start to control the contamination of the vegetable oils used in the elaboration of these products, in order to reduce the exposure of consumers to excessive amounts of potentially carcinogenic compounds.

Ocupação do mercado de trabalho em Educação Fisica na cidade de Campinas, devido a formação profissional

Universidade Estadual de Campinas. Faculdade de Educação Física

Mercado de trabalho em educação fisica ;significado da intervenção profissional a luz das relações de trabalho e da construção da carreira

Universidade Estadual de Campinas. Faculdade de Educação Física

Manejando o lazer em areas de potencial ecoturistico : o caso do Colegio Agricola de Jundiai/RN

Universidade Estadual de Campinas . Faculdade de Educação Física