Perda de carga AC:mental em tubos janelados

Este trabalho, realizado no Laboraterio de Hidraulica da Universidade Federal de Vicosa, teve o objetivo de determinar a perda de carp acidental devida inserctio de janelas de 31,2 mm de diametro inferno em tubulacao de 143 mm de diametro interne, (diametro nominal de 150 mm), fabricadas pela "Tubos e ConexOes Tigre S. A." Foram determinados as coeficientes de perda de carga acidental, levando ern conta a vazio na tubulacao a montante da janela (K 1), a vazab da janela (K2), a vazao rn6dia da tubulagio (Ks) e a vazAo fictfcia da tubulacio (K4), confonne o gran de abertura da janela. Considerando os resultados obtidos e a simplicidade dos &pacifies, recomenda-se o coeficiente de perda de carga K2

<b>Construction and calibration of a bar weighing lysimeter

Generally, standard lysimeters include a lever-load cell scale, which has become expensive compared to new electronic equipment available for experimental purposes. Currently, lysimeters containing weighing bars with up to 4 load cells are economically feasible. This goal of this study was to present the construction and calibration of four weighing lysimeters built using two rectangular tanks, with a surface area of 1.35 m2 (1 m by 1.35 m) and a depth of 1.5 m, loaded on two weighing bars. Each bar had two high accuracy loading cells connected to a junction box and a datalogger by a coaxial cable. Calibration of each lysimeter was performed after field installation. The results showed a linear response (R2 > 0.9999) of electric signal (mV) to mass increase or decrease (kg) with minimum hysteresis. The mean absolute error of the mass estimate (0.0245 to 0.2844 equivalent-mm) and a Willmott index between the observed and estimated data (d = 1.0000) indicate the high precision of the new equipment. The results allow concluding that the lysimeters in this study are appropriate for estimating evapotranspiration and other components of soil water balance