A computing tool based on an intelligent algorithm generates new alternatives for an early crack detection on flat concrete slab in a surface testing. First, a system able to autonomously detect a surface crack, by means of a digital image processing system has been developed. This system carries on an effective selection of data by an algorism bound to a specialized MATLAB software that can assess in full detail the surface conditions of a concrete slab, and finding out any affected spot.

The development of a prototype linear solar collector Type Fresnel, has a purpose the use of direct solar heat radiation for water heating and/or steam production, as an alternative to supply conventional water heating systems or steam generators, which consume energy from fossil fuels. For the development of the system, used the solar radiation of the UTS, located in Bucaramanga, Colombia, is identify the mathematical models to perform the sizing, then materials based on technical specifications and availability in Colombia, in order to perform the assembly and field tests, measuring the ambient and in the collector temperature to determine the efficiency of the model. It should be noted that, the model presented does not have a control system for flow, temperature, pressure and level, it has no solar tracking of any kind; Its movement was done manually with each reflex. Finally, the model does not have a hydraulic system forced, and has a preheater at the entry of the concentration point.

Design and construction of a solar tracking system for Linear Fresnel Concentrator

The purpose of this study was to develop a simple viscoelastic model to characterize the mechanical properties of chests during manual chest compressions in pre-hospital cardiopulmonary resuscitation (CPR). Force and acceleration signals were extracted from CPR monitors used during pre-hospital resuscitation attempts on adult patients. Individual chest compressions were identified and segmented from the chest displacement computed using the force and acceleration. Each compression-recoil cycle was characterized by its elastic coefficient k (a measure of stiffness) and its compression and recoil damping coefficients, d_c and d_r, respectively (measures of viscosity). We compared the estimated and the calculated chest displacement to assess the goodness of fit of the model. We characterized the chest of patients at the beginning of CPR in relation to sex and age, and their variation as CPR progressed. A total of 1,156,608 chest compressions from 615 patients were analysed. Mean (95% CI) coefficient of determination R² for the viscoelastic model was 97.9% (97.8-98.1). At the beginning of CPR, k was 104.9 N⋅cm^-1 (102.0-107.8), d_c was 2.868 N⋅s⋅cm^-1 (2.751-2.984) and d_r was 4.889 N⋅s⋅cm^-1 (4.648-5.129). Damping during recoil was significantly higher than during compression. Stiffness was lower in women than in men. There were no differences in damping coefficients with sex but a higher d_r with increasing age. All model coefficients decreased with compression count, with an overall decrease after 3,000 chest compressions of 34.6%, 48.8% and 37.2%, respectively. The model accurately described adult chest mechanical properties during CPR, highlighting differences between compression and recoil, sex and age, and a progressive reduction in chest stiffness and viscosity along resuscitation. Our findings may merit further investigation into whether patient-tailored and time-sensitive chest compression technique may be appropriate.

In the present document, the Cepstrum transform and the analysis of principal components were used to differentiate amplitudes in the mechanical vibrations produced by unbalance and misalignment with respect to a reference group. This document requires three stages. It begins with levelling in order to establish the control group. The unbalancing was carried out with a known mass located in the two radial distances of the first and second flywheels. The misalignment was made by running the sliding supports back 0.5, 1.0 and 1.5 degrees. In the second stage, Matlab algorithms were created for both cepsctrum and main component analysis. In the last stage the obtained data were analyzed identifying the differences that may exist in the analyzed records. The project focused on the use of Matlab to find differences at a frequency of 30 Hz. The results obtained made it possible to determine that it is possible to find differences with the proposed methodology.