Artificial intelligence to predict inhibition performance of pitting corrosion

This work aims to compare several algorithms for predicting the inhibition performance of localized corrosion. For this more than 400 electrochemical experiments were carried out in a corrosive solution containing an inorganic inhibitor. Pitting potential is used to indicate the performance of the inhibitor/oxidant mixture to prevent pitting corrosion. At the end of the electrochemical program a file containing all the experimental results has been prepared and submitted to several algorithms. Through a training phase each algorithm uses a set of experimental results to adjust its parameters and another set to predict the pitting potential starting from the properties and the chemical composition of the solution. The prediction performance of an algorithm is estimated by the  difference between experimental pitting potential and the calculated one. The order of performance of the algorithms is: GA-ANN > LS-SVM > PSO-ANN > ANN >ANFIS > KNN > RT > KBP > LDA.Key words: Pitting potential, Corrosion inhibitor, Performance prediction, Artificial intelligence

THEORETICAL AND EXPERIMENTAL STUDY OF THERMAL PERFORMANCE WITHIN A COUNTERFLOW WET COOLING TOWER

This study is interested on experimental and theoretical of heat and mass transfer phenomena in a counter-flow wet cooling tower. A simplified thermal model has been used to simulate the thermal behavior and the performance of the tower. The calculation of the heat and mass transfer parameters to determine the characteristics of the good operation of the tower. Eight experimental manipulations were conducted to study the influence of various parameters (such as: thermal cooling load, the flow of water and air) on the thermal performance of the tower. The results obtained show that the increase in cooling load contributes to a considerable reduction in the effectiveness of the tower, as well as the increase in the water flow is used to decrease the performance of the tower, while the increase in airflow is used to improve considerably the different parameters of performance. It can be seen that the results obtained by simulation coincide quite well with the experimental results. The minor discrepancies between the present simulation and experimental measurements can be attributed to the measurements uncertainties and simulation accuracy

OPTIMIZATION OF LEARNING ALGORITHMS IN THE PREDICTION OF PITTING CORROSION

This work is part of a scientific research program whose objective is to prevent pitting corrosion of an open cooling circuit of a nuclear installation. Various corrosion inhibitors have been studied. The performances of pitting corrosion inhibition were discussed and compared on the basis of several criteria. The experimental data were collected in a large table and subjected to algorithms in order to construct models for predicting corrosion inhibition performance. We used four algorithms: Genetic Algorithm-Artificial Neural Network (GAANN); Least Squares-Support Vector Machine (LS-SVM), K Nearest Neighbors (KNN) and Regression Tree (RT). We optimized the data fraction reserved for learning and we sought to optimize the parameters specific to each algorithm. The efficiency of pitting inhibition increases in the following order: HCO3- < H2PO4- < CO32- < PO4-2 < PO4 3- < SiO3 2- < MoO4 2- < WO4 2-. Our results showed that the order of performance of the algorithms is: RT < KNN < LS-SVM < GA-ANN

Ecosystemes steppiques(Cas de Brezina– El Bayadh)

Postprint (published version

Contribution a la comprehension de la qualité des sols de la steppe algerienne (Cas du secteur El Bayadh-Brezina, ouest de l'Algerie)

Postprint (published version

Restoring the valence-shell stabilization in Nd-140

A projectile Coulomb-excitation experiment was performed at the radioactive-ion beam facility HIE-ISOLDE at CERN to obtain E2 and M1 transition matrix elements of Nd-140 using the multistep Coulomb-excitation code GOSIA. The absolute M1 strengths, B(M1; 2(2)(-) -> 2(1)(+)) = 0.033(8)mu(2)(N), B(M1 ; 2(3)(+) -> 2(1)(+)) = 0.26(-0.10)(+0.11)mu(2)(N), and B(M1; 2(4)+ -> 2(1)(+)) <0.04 mu(2)(N) identify the 2(3)(+) state as the main fragment of the one-quadrupole-phonon proton-neutron mixed-symmetry state of Nd-140. The degree of F-spin mixing in Nd-140 was quantified with the determination of the mixing matrix element VF-mix <7(-7)(-13) keV.Peer reviewe

Quantitative study on the changes of Karst groundwater level and hydrochemistry in Jinci spring catchment, Shanxi, China

Since Jinci spring ceased to flow on April 30, 1994, it has never been reflowed, which seriously affects the sustainable utilization of karst groundwater. The purpose of this paper is to provide the basis for the reflow of Jinci spring and the sustainable protection for karst groundwater. Based on the long-term monitoring data from 1994 to 2014, this paper accurately quantifies the changes in the quantity and hydrochemistry of karst groundwater resources. By means of the Mann–Kendall trend test method, this paper analyzes the variation trends of karst groundwater level, EC, and SO42− in Jinci spring catchment. Monitoring data show that the groundwater level in the karst aquifer declined by 2.32 m from 1994 to 2008, which is equivalent to a loss of 3.3 Mm3 in aquifer storage, while the groundwater level rose by 17.67 m from 2009 to 2014, which constitutes a gain of 25.2 Mm3. The results indicate that (1) karst groundwater level showed a rising trend, which was mainly controlled by the rainfall, exploitation of karst groundwater, and the Fenhe River leakage; (2) groundwater salinity varied greatly and showed an increasing trend: increasing order of 47.83% for the six major ions, 37.52% for EC, and 3.34% for pH; (3) the increase of groundwater salinity is governed by the increase in rainfall salinity, the increase in groundwater runoff time, the recharge of the Fenhe River to groundwater, the increase of sewage in spring catchment, and the ease of solubility of carbonate rocks. The results of this study are of great significance for predicting the groundwater level and salinity of karst aquifer and ensuring the safety of drinking water in Jinci spring catchmen

Quadrupole and octupole collectivity in the semi-magic nucleus 80206Hg126

The first low-energy Coulomb-excitation measurement of the radioactive, semi-magic, two proton-hole nucleus 206Hg, was performed at CERN's recently-commissioned HIE-ISOLDE facility. Two γ rays depopulating low-lying states in 206Hg were observed. From the data, a reduced transition strength B(E2;21+→01+)=4.4(6) W.u. was determined, the first such value for an N=126 nucleus south of 208Pb, which is found to be slightly lower than that predicted by shell-model calculations. In addition, a collective octupole state was identified at an excitation energy of 2705 keV, for which a reduced B(E3) transition probability of 30−13+10 W.u. was extracted. These results are crucial for understanding both quadrupole and octupole collectivity in the vicinity of the heaviest doubly-magic nucleus 208Pb, and for benchmarking a number of theoretical approaches in this key region. This is of particular importance given the paucity of data on transition strengths in this region, which could be used, in principle, to test calculations relevant to the astrophysical r-process

Dissipative Capacity Analysis of Steel Buildings using Viscous Bracing Device

Abstract — Energy dissipation Systems in civil engineering structures are sought when it comes to removing unwanted energy such as instability, earthquake and wind. Among these systems, there is the combination of structural steel frames with passive energy dissipation provided by Fluid Viscous Dampers (FVD). This device is increasingly used to provide better seismic protection for existing as well as new buildings and bridges. A 3 D numerical investigation is done considering the seismic response of a twelve-story steel building moment frame with diagonal FVD that have linear force versus velocity behaviour. Nonlinear time history, which is being calculated by Fast nonlinear analysis (FNA), of Boumerdes earthquake (Algeria, May 2003) is considered for the analysis and carried out using the SAP2000 software and comparisons between unbraced, braced and damped structure are shown in a tabulated and graphical format. The results of the various systems are studied to compare the structural response with and without this device of the energy dissipation thus obtained were discussed. The conclusions showed the formidable potential of the FVD to improve the dissipative capacities of the structure without increasing its rigidity. It is contributing significantly to reduce the quantity of steel necessary for its general stability

Mineralogical stabilization of Ternesite in Belite Sulfo-Aluminate Clinker elaborated from limestone, shale and phosphogypsum

This paper investigates the mineralogical evolution of sulfoaluminate clinker elaborated from moroccan prime materials limestone, shale and phosphogypsum as a byproduct from phosphoric acid factories. The advantage of the production of this type of clinker is related to the low clinkerisation temperature which is known around 1250°C, and to less consumption quantity of limestone thus enabling less CO2 emissions during the decarbonation process compared to that of Portland cement. In this study we determine the stability conditions of belite sulfoaluminate clinker containing belite (C2S) ye’elimite (C4A3$) and ternesite (C5S2$). The hydration compounds of this clinker are also investigated. The monitoring of the synthesized and hydrated phases is performed by X-Ray Diffraction and Infrared spectroscopy. The results show the formation of ternesite at 800°C and the stabilization of clinker containing y’elminite, belite and ternesite at temperatures between 1100 and 1250°C