Electrochemical Hydrogen in Metals - Can we Effectively Control this Harm?

Abstract

The problem under consideration concerns the prevention of absorption of hydrogen in the processes of corrosion and electroplating of all industrially used metals with the aim of the modification of chemical and physical properties of base metal surface. Its properties change towards better brightness and soldering, minimal porosity and hydrophilicity of surface, increase of hardness and wear resistance. All these properties were evaluated by means of appropriate test equipment. Residual stresses in Cr coating by phase transformation, beginning in the electroplating process, acted in combination with absorbed huge quantity of hydrogen in intrinsic defects in the steel base. Internal stresses in the base/coating region resulted in severe deterioration of the durability of steel parts, as identified by static or sign-variable fatigue tests. The newstress-steptechnique makes possible an analysis of H content as a function of the depth in base metals and its distribution in coating metal .

Modelling Macroscopic Properties of Organic Species on the Basis of Quantum Chemical Analysis (on an Example of Inhibiting Efficiency of Ureides and Acetylides against Corrosion)

“…In Table 7, EDTA designate ethylendiaminetetraacetic acid derivatives, NTA -nithrilotriacetic acid derivatives, and MATA -derivatives of methylaminetetraacetic acid. [5][6][7][8]10], the results brought above in Tables 7 and 8 mean that the inhibitive properties of the selected ureides under chosen conditions are based on electron donating rather than accepting properties of their molecules.…”

“…By means of different quantum chemical methods (PM/3, MP/3, MNDO, ab initio), various properties of individual chemical species (including organic) have been rather successfully explained so far: efficiencies as anti-corrosion inhibitors [1][2][3][4][5][6][7][8][9][10] (also as inhibitors of hydrogen absorption by metals) [5][6][7][8][9][10], efficiencies of species as biocides e.g. against sulfate reducing bacteria (SRB) [7][8][9][10]; wide range (scope) of medical (pharmaceutical) [21] or, generally, biological activity [11] or properties in relation to important chemical applications (EFG in NQR) [12] of various individual substances can also be well explained by means of analysis of certain quantum chemical characteristics -descriptors QCD [13] available for the respective molecules, provided the chemical structure of corresponding species is known.…”

Virtual machine optimization to achieve energy efficient optimum resource utilization in cloud data center

“…The combination contributes to the trade off between asset use and energy use. Similarly, VM movement (13) allows the dynamic management of resources while reducing support costs. On the other hand, changes in virtualization leads to a significant decline in virtual machine overhead, thus increasing the cloud's energy productivity.…”