Detection of the thickness of scale on the inner surface of water pipes by infrared thermography
The infrared thermography technique developed in the present study was successfully applied to determine the scale thicknesses of the steel pipe. We aim to estimate the thickness of the scale on the inner surfaces by calculation of the maximum temperature of the infected pipe heated surface. Dimensions of the pipe and those of the layer of scale are taken as geometrical parameter. We have studied the effect of each one on the thermal response of the considered structure. These information are important for determining dangerous state of water distribution network.
FORMATION OF CaCO3 PARTICLE AND CONDUCTIVITY OF Na2CO3 AND CaCl2 SOLUTION UNDER MAGNETIC FIELD ON DYNAMIC FLUID SYSTEM
Hard  water  causes  the  CaCO3  scale  formation  on  the  pipe  walls and  heat  exchanger  equipments  in  industrial  or domestic  water  processes.  A  great  number  of  experimental  researches  on  the  prevention  of the  CaCO3  precipitation process  by  magnetic  field  have  been  carried  out.  In  this  research,  Na2CO3  and  CaCl2  solutions  was  magnetized  in  the circulated  flow  condition  (dynamic  fluid  system).  The  velocity  of  fluid  and  the  circulation  time  was  modified  to examine  its influences  to  the  magnetization  process.  CaCO3  content  was measured  by  titration  method  of  EDTA complexometry.  Conductivity  test  was  conducted  to  find  out  hydrate  ion  bonding.  The  results  showed  that magnetization increased the CaCO3 formation and the optimum process reaches for 10 minutes circulation on 0.554 m/s of flow rate. Magnetic field decreases the conductivities of Na2CO3 and CaCl2  solution, hence reduced the ion hydrate bonding. These results showed that magnetization on Na2CO3 and CaCl2 ionic solution was effective in controlling the CaCO3 formation by increasing CaCO3 precipitation.
Numerical method applied to the nondestructive characterization of the cracks in the roadways
Abstract This article proposes numerical simulations for the thermal nondestructive characterization. It relates to the thermal nondestructive study of defects of cracks type in the roadways. The model used is a semi-rigid roadway containing cracks of various positions and sizes. The thermal behavior of the roadway, according to geometrical and thermophysical parameters of the defect, is analyzed. A constant density of heat flow is applied to the higher face of the wearing layer of the roadway, the face of lower part of the base layer being maintained at a constant temperature. The influence of the various geometrical parameters of the defect (size, thickness and position) is studied and the thermographical image of the face of entry is simulated then analyzed. The numerical method adopted for the resolution of this problem is that of the finite elements. 1. Introduction The evaluation of the state of the roadways is an essential sector to identify the afflicted places, and for the planning and the assignment of the budgets of maintenance. The vehicular traffic worsens the cracks and propagates them towards surface, which leads to the deterioration of the external and fundamental layers [1]. For this reason, the first identification of the weak zones and cracks make it possible to departments of transport to develop remedies to attenuate the negative impacts and to lengthen the lifespan of the roadways. The ideal scenario in the evaluation of the defects is based on nondestructive approaches to prevent to obstruct the vehicular traffic. In this article, we will draw up a numerical study of the response of a semi-rigid roadway, containing defects of the cracks type, with a thermal wave and the influence of such defects on the thermographical image simulated on the road surface. Indeed, When a material is thermically requested, (e.g. reheating in a natural way by the sun), diffuse heat in material and the presence of a defect within the material (e.g. a crack) generally modify the heat flux through the structure taking into account the difference between the thermophysical parameters of material and those of the defect. It follows from there the appearance of a more or less hot zone on the surface compared to close material deprived of anomaly [2, 3]. To be able to detect the presence of an anomaly in the structure, the change which flow undergoes must be sufficient so that the contrast of temperature, between the healthy zones and the problematic ones, is significant and detectable thereafter.