Inhibiting effects of 2-mercapto-1-methylimidazole on copper corrosion in 0.5M sulfuric acid

AbstractThe inhibiting efficiency of 2-mercapto-1-methylimidazole (MMI) on copper corrosion in sulfuric acid was investigated at 30°C. Its effectiveness was assessed through electrochemical impedance spectroscopy, potentiodynamic polarization and gravimetric measurements. The results of study reveal that the inhibition efficiency of MMI depends on its concentration and attains approximately 81% at 10−4M. The inhibitor was adsorbed on the copper surface according the Langmuir adsorption isotherm model. The value of standard free energy of adsorption was calculated from this isotherm

Synthesis Characterization And Photopolymerization Of Novel Phosphonated Materials

New phosphonated cross-linked materials were synthesized from telomers obtained by reaction between 10-undecenol and dialkyl hydrogenphosphonates. Telomers were then converted to materials resins by methacrylation reactions. Finally, photopolymerization of the different materials synthesized was achieved and influence of the nature of the phosphonate group (diester, monoacid and diacid) was also evaluated.New phosphonated cross-linked materials were synthesized from telomers obtained by reaction between 10-undecenol and dialkyl hydrogenphosphonates. Telomers were then converted to materials resins by methacrylation reactions. Finally, photopolymerization of the different materials synthesized was achieved and influence of the nature of the phosphonate group (diester, monoacid and diacid) was also evaluated

THE USE OF NEW TECHNOLOGIES IN THE RESTORATION AND CONSERVATION OF BUILT CULTURAL HERITAGE/ THE CASE OF THE STATUE OF FOUARA, SETIF, ALGERIA

The present paper deals with the techniques using the laser scanner survey in the restoration of the statue of Fouara in Setif, Algeria. This statue which is made of marble was realized by Francis de St Vidal in 1899 that represents a nymph which is a part of the fountain, publicly displayed in the center of the city's main plaza. On 18 December 2018, a man defaced the statue, removing the facial features and breasts with a hammer and chisel.As a matter of fact, the build cultural heritage in Algeria is in danger from attacks and reaction time deterioration with age. Following the day of the incident, our team has been called to use a previous scanner laser survey of the nymph that was stored in our cultural heritage monument database in order to help the restoration of the missing part of the nymph (the face and the breast. as matter of fact, the original laser scanning survey provided a helpful and accurate details to support the restoration of the nymph.</p

Synthesis, characterisation and antifungal activity of a series of Cobalt(II) and Nickel(II) complexes with ligands derived from reduced N, N′-o-Phenylenebis(Salicylideneimine)

The synthesis and characterisation by elemental analysis, conductivity, FTIR, UV–Visible, ESR and magnetic measurements are described for a series of complexes of nickel(II) and cobalt(II) with three ligands (H2L1–3) derived from reduced N, N′-o-Phenylenebis(salicylideneimine). The complexes formed are identified as neutral species, where the ligands are coordinated through N and O donor atoms. The formulae obtained for the complexes are: [CoL(H2O)2] with octahedral geometry and [NiL] with tetrahedral geometry. Their antifungal activity is evaluated towards human pathogenic fungi including yeasts of the Candida genus, some opportunistic moulds belonging to the Aspergillus, Scedosporium genus and some dermatophytes. The cobalt complexes show a significant growth inhibition of yeasts tested and also to fungi of the genus Scedosporium which is of interest because these fungi are usually poorly susceptible to current antifungal including Amphotericin B and Itraconazole, chosen as reference in this study. The activity data show that the metal complexes are more potent than the parent ligand

Synthesis, characterization and antifungal activity of a series of manganese(II) and copper(II) complexes with ligands derived from reduced N,N′-O-phenylenebis(salicylideneimine)

A series of manganese(II) and copper(II) complexes with reduced Schiff bases derived from o-phenylenediamine has been prepared and characterized by elemental analysis, TG measurements, ESR, magnetic measurements, FTIR, UV–Visible spectra and conductivity. These complexes were found to be [MnL(H2O)n] and [CuL](H2O)n species with n = 0–2. Their antifungal activity was evaluated on different human fungi including yeasts of the Candida genus (C. albicans, C. glabrata, C. tropicalis and C. parapsilopsis) some opportunistic moulds belonging to the Aspergillus (A. fumigatus, A. terreus and A. flavus), Scedosporium genus (S. apiospermum and S. prolificans) and some dermatophytes (M. gypseum, M. persicolor, T. mentagrophytes, M. canis and T. tonsurans). The manganese complexes showed a significant growth inhibition of the dermatophytes tested and fungi of the genus Scedosporium. This is very interesting as these fungi are usually poorly susceptible to current antifungal including Amphotericin B and Itraconazole chosen as reference in this study

Spectrometric Analyses, Structure and Voltammetric Study of Nickel(II) with N[(1E) Phenylmethylene N2[2(2Hydroxyphenylmethylene]Amino ethyl) Imidazolidin-1-yl Ethylamine

The reaction of N[(1E) phenylmethylene N2[2(2hydroxyphenylmethylene]amino ethyl) imidazolidin -1-yl ethylamine ligand (H 3 L) with nickel(II) salt, by heating at 40°C and addition of NaOH in excess, was made by eliminating of the phenol substituted imidazolidine ring, giving the mononuclear nickel(II) complex of the deprotonated bis-salicylaldehyde-triethylenetetramine (L −2 ). UV-Vis, FTIR and structural resolution show an octahedral geometry for [NiL]·6H 2 O complex. This compound has been characterized by single crystal X-ray diffraction study. This technique reveals that Ni-H 2 L involves a high-spin nickel(II) ion within a pseudo-octahedral geometry. The Ni(II) complex has NiN 4 O 2 coordination sphere as established from a crystal structure determination. The crystals of Ni(II) complex are tetragonal, space group P4/ncc, a = b = 19.348 A; c = 13.201 A. R(F) value (0.0528) found shows a very good precision of the determined geometrical parameters. Cyclic voltammetry of nickel complex is indicative of electronic communication between the nickel center via Schiff base ligand. The results obtained confirm the imidazolidine ring-cleavage reaction and the elimination of the substituted phenol on this ring and show that the presence of H 3 L ligand around the metallic center stabilizes the oxidation of the Ni(II) to Ni(III)

Measurement of the Beam-Recoil Polarization in Low-Energy Virtual Compton Scattering from the Proton

Double-polarization observables in the reaction $\vec{e}p \rightarrow e'\vec{p'}\gamma{}$ have been measured at $Q^2=0.33 (GeV/c)^2$. The experiment was performed at the spectrometer setup of the A1 Collaboration using the 855 MeV polarized electron beam provided by the Mainz Microtron (MAMI) and a recoil proton polarimeter. From the double-polarization observables the structure function $P_{LT}^\perp$ is extracted for the first time, with the value $(-15.4 \pm 3.3 (stat.)^{+1.5}_{-2.4} (syst.)) GeV^{-2}$, using the low-energy theorem for Virtual Compton Sattering. This structure function provides a hitherto unmeasured linear combination of the generalized polarizabilities of the proton

Zirconia and hafnia polymorphs: Ground-state structural properties from diffusion Monte Carlo

Zirconia (zirconium dioxide) and hafnia (hafnium dioxide) are binary oxides used in a range of applications. Because zirconium and hafnium are chemically equivalent, they have three similar polymorphs, and it is important to understand the properties and energetics of these polymorphs. However, while density functional theory calculations can get the correct energetic ordering, the energy differences between polymorphs depend very much on the specific density functional theory approach, as do other quantities such as lattice constants and bulk modulus. We have used highly accurate quantum Monte Carlo simulations to model the three zirconia and hafnia polymorphs. We compare our results for structural parameters, bulk modulus, and cohesive energy with results obtained from density functional theory calculations. We also discuss comparisons of our results with existing experimental data, in particular for structural parameters where extrapolation to zero temperature can be attempted. We hope our results of structural parameters as well as for cohesive energy and bulk modulus can serve as benchmarks for density-functional theory based calculations and as a guidance for future experiments

Noncovalent Interactions by QMC: Speedup by One-Particle Basis-Set Size Reduction

While it is empirically accepted that the fixed-node diffusion Monte-Carlo (FN-DMC) depends only weakly on the size of the one-particle basis sets used to expand its guiding functions, limits of this observation are not settled yet. Our recent work indicates that under the FN error cancellation conditions, augmented triple zeta basis sets are sufficient to achieve a benchmark level of 0.1 kcal/mol in a number of small noncovalent complexes. Here we report on a possibility of truncation of the one-particle basis sets used in FN-DMC guiding functions that has no visible effect on the accuracy of the production FN-DMC energy differences. The proposed scheme leads to no significant increase in the local energy variance, indicating that the total CPU cost of large-scale benchmark noncovalent interaction energy FN-DMC calculations may be reduced.Comment: ACS book chapter, accepte

Awareness of cognitive decline trajectories in asymptomatic individuals at risk for AD

Background: Lack of awareness of cognitive decline (ACD) is common in late-stage Alzheimer’s disease (AD). Recent studies showed that ACD can also be reduced in the early stages. Methods: We described different trends of evolution of ACD over 3 years in a cohort of memory-complainers and their association to amyloid burden and brain metabolism. We studied the impact of ACD at baseline on cognitive scores’ evolution and the association between longitudinal changes in ACD and in cognitive score. Results: 76.8% of subjects constantly had an accurate ACD (reference class). 18.95% showed a steadily heightened ACD and were comparable to those with accurate ACD in terms of demographic characteristics and AD biomarkers. 4.25% constantly showed low ACD, had significantly higher amyloid burden than the reference class, and were mostly men. We found no overall effect of baseline ACD on cognitive scores’ evolution and no association between longitudinal changes in ACD and in cognitive scores. Conclusions: ACD begins to decrease during the preclinical phase in a group of individuals, who are of great interest and need to be further characterized. Trial registration: The present study was conducted as part of the INSIGHT-PreAD study. The identification number of INSIGHT-PreAD study (ID-RCB) is 2012-A01731-42