Knowing the quality of concrete is very important, because this type of material is part of the design and implementation of most structures such as bridges, buildings, tunnels, among others, in this investigation non-destructive tests were carried out on test specimens of using ultrasound, which were designed and developed in the concrete laboratory at Santo Tomas University in Bogotá D.C. taking into account for its preparation a dosage of the estimated concrete mixture in order to obtain specimens with a compressive strength of 3500psi, 2500psi and 1500psi, in such a way, the specimens were allowed to cure for a period of 28 days, ensuring that they achieved their maximum compression strength. As mentioned above, non-destructive ultrasound tests were applied in order to determine the quality of the manufactured concrete specimens, thus, an ultrasound system is proposed that makes it possible to pass an acoustic wave through a concrete specimen, this was proposed with the purpose of measuring the velocity with which the wave passes in the volume of this material, known as the ultrasonic pulse velocity. Therefore, the respective velocities for each of the concrete specimens were measured, thus finding a relationship between the ultrasonic pulse velocity and the compressive strength, which finally makes possible the evaluation of the manufactured concrete specimens.

We estimated the frequencies of serum butyrylcholinesterase (BChE) alleles in three tribes of Mapuche Indians from southern Chile, using enzymatic methods, and we estimated the frequency of allele BCHE*K in one tribe using primer reduced restriction analysis (PCR-PIRA). The three tribes have different degrees of European admixture, which is reflected in the observed frequencies of the atypical allele BCHE*A: 1.11% in Huilliches, 0.89% in Cuncos, and 0% in Pehuenches. This result is evidence in favor of the hypothesis that BCHE*A is absent in native Amerindians. The frequencies of BCHE*F were higher than in most reported studies (3.89%, 5.78%, and 4.41%, respectively). These results are probably due to an overestimation of the frequency of allele BCHE*F, since none of the 20 BCHE UF individuals (by the enzymatic test) individuals analyzed showed either of the two DNA base substitutions associated with this allele. Although enzymatic methods rarely detect the presence of allele BCHE*K, PCR-PIRA found the allele in an appreciable frequency (5.76%), although lower than that found in other ethnic groups. Since observed frequencies of unusual alleles correspond to estimated percentages of European admixture, it is likely that none of these unusual alleles were present in Mapuche Indians before the arrival of Europeans.

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