Studies of concentration and temperature dependencies of precipitation kinetics in iron-copper alloys using kinetic monte carlo and stochastic statistical simulations

The earlier-developed ab initio model and the kinetic Monte Carlo method (KMCM) are used to simulate precipitation in a number of iron-copper alloys with different copper concentrations x and temperatures T. The same simulations are also made using the improved version of the earlier-suggested stochastic statistical method (SSM). The results obtained enable us to make a number of general conclusions about the dependencies of the decomposition kinetics in Fe-Cu alloys on x and T. We also show that the SSM describes the precipitation kinetics in a fair agreement with the KMCM, and employing the SSM in conjunction with the KMCM enables us to extend the KMC simulations to the longer evolution times. The results of simulations seem to agree with available experimental data for Fe-Cu alloys within statistical errors of simulations and the scatter of experimental results. Comparison of results of simulations to experiments for some multicomponent Fe-Cu-based alloys enables us to make certain conclusions about the influence of alloying elements in these alloys on the precipitation kinetics at different stages of evolution.Comment: 18 pages, 17 postscript figures, LaTe

New derivatives of isoniazide, pyrazinamide and 2-aminobutanol and their anti-tubercular activity

508-510<span style="font-size:14.0pt;mso-bidi-font-size:8.0pt;font-family:Fd531191-Identity-H; mso-bidi-font-family:Fd531191-Identity-H;color:#0F0F0F">Some new s-trizine derivatives having isoniazide, pyrazinamide <span style="font-size:14.0pt;mso-bidi-font-size:8.0pt;font-family:Fd531191-Identity-H; mso-fareast-font-family:" times="" new="" roman";mso-bidi-font-family:fd531191-identity-h;="" color:#0f0f0f;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"="">and 2-aminobutanol moeity have been synthesized by condensation of substituted s-triazene <span style="font-size:15.0pt;mso-bidi-font-size:9.0pt;font-family:Fd184550-Identity-H; mso-fareast-font-family:" times="" new="" roman";mso-bidi-font-family:fd184550-identity-h;="" color:#0f0f0f;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"="">(<i style="mso-bidi-font-style: normal">2a, b, <span style="font-size:14.0pt;mso-bidi-font-size:8.0pt;font-family:Fd531191-Identity-H; mso-fareast-font-family:" times="" new="" roman";mso-bidi-font-family:fd531191-identity-h;="" color:#0f0f0f;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"="">c<span style="font-size:14.0pt;mso-bidi-font-size:8.0pt; font-family:Fd531191-Identity-H;mso-fareast-font-family:" times="" new="" roman";="" mso-bidi-font-family:fd531191-identity-h;color:#0f0f0f;mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">) with isoniazide, pyrazinamide and 2-aminobutanol. The products have been characterized by spectral data and evaluated for antitubercular activity. Some of them have shown moderate antitubercular activity values in terms of μg/mL determined by broth dilution technique.</span

Interfacial Structure and Photocatalytic Activity of Magnetron Sputtered TiO2 on Conducting Metal Substrates

International audienceThe photocatalytic behavior of magnetron sputtered anatase TiO2 coatings on copper, nickel, and gold was investigated with the aim of understanding the effect of the metallic substrate and coating-substrate interface structure. Stoichiometry and nanoscale structure of the coating were investigated using X-ray diffraction, Raman spectroscopy, atomic force microscope, and scanning and transmission electron microscopy. Photocatalytic behavior of the coating was explored by using optical spectrophotometry and electrochemical methods via photovoltage, photocurrent, and scanning kelvin probe microscopy measurements. The nature of the metal substrate and coating-substrate interface had profound influence on the photocatalytic behavior. Less photon energy was required for TiO2 excitation on a nickel substrate, whereas TiO2 coating on copper showed a higher band gap attributed to quantum confinement. However, the TiO2 coating on gold exhibited behavior typical of facile transfer of electrons to and from the CB, therefore requiring only a small amount of photon energy to make the TiO2 coating conductive