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The determination and the use of soil hydraulic conductivity functions obtained from internal drainage experiments, performed in field soil profiles, using the Darcy–Buckingham flux gradient approach are discussed. Details of the calculation procedures indicate the sensitivity of the methodologies used, and of the most commonly adopted model for K(θ) relations: K(θ)=K0.exp[−γ.(θ0−θ)]. It is shown that the unit total water potential gradient cannot prevail in the whole soil profile during internal drainage after infiltration and that, as a consequence of this assumption, several methods of hydraulic conductivity determination yield K(θ) relations which are depth dependent, even for homogeneous soils. The difficulties of using K(θ) relations in modeling soil water dynamics due to their very strong exponential behaviour are also discussed.

An internal drainage experiment was conducted to examine soil water content variability in space and in time. It is shown that the flux-gradient model used to describe water flow in field soil profiles, based on the Darcy–Buckingham equation, yielded results of extreme variability and questionable validity. The problem lies in the representativeness of a site due to soil variability, horizontally and vertically in time, which added to the character of the hydraulic conductivity versus soil water content relation, which in many cases can be approximated by exponential functions, leads to coefficients of variation up to 170% in the estimation of soil hydraulic conductivity values.

A neutron probe calibration correction is proposed in order to reduce soil water content variability, assumed to be a consequence of improper calibrations relations. The time stability of spatially measured soil water content data is used to correct the intercepts of linear calibration relations. This procedure reduced the coefficients of variation of soil water content data from 4 to less than 2% in a Rhodic Kanhapludalf.

Samples of concrete for popular habitation (0.1×0.03×0.1 m) and cellular concrete (0.1×0.05×0.1 m) were submitted to water vertical ascending infiltration. The moisture content spatial and temporal evolution of each sample it was monitored in three halfway positions in a same horizontal line, applying the gamma rays transmission method. The data were taken with a 137Cs (3.7×1010 Bq, 0662 MeV) source, Nal (Tl) of 2×2″ detector coupled to gamma ray spectrometry standard electronic with multichannel analyzer and a micrometric table. For the popular habitation concrete, there was a clear correlation between wetting profiles and concrete strength. The cellular concrete showed a wetting profile compatible to its greater porosity.

A method based on the generalized optical theorem is proposed for the determination of the total reaction cross section from elastic angular distributions. This method was applied to 16 complete elastic angular distributions of the 12 C + 16 O at energies between E c.m =8.55 MeV and E c.m = 26.74 MeV. Some of the angular distributions were measured at the Sao Paulo Pelletron Laboratory. Angular distributions measured by the Erlangen and Saclay groups were also used. The reaction cross section is compared with fusion measurements and with σ R obtained by indirect methods. The existence and conditions for the observation of the nuclear forward glory scattering are investigated.

The excitation functions of the reactions {sup 24}Mg({sup 16}O,{sup 20}Ne){sup 20}Ne and {sup 24}Mg({sup 16}O,{sup 12}C){sup 28}Si were measured at {theta}{sub c.m.}=90{degree} and 70{degree}, respectively, in the energy interval of 25 to 34 MeV in steps of 240 keV. They display strong structures with widths of 1 to 2 MeV and are compared to calculations including the coupling to higher orders between elastic and {alpha}-transfer channels, through the dynamic {alpha}-transfer polarization potential.