Abstract Continuing the research in the field of complex compounds, the authors present in this paper the synthesis and characterization of a new compound of Cu(II) with the ligand 1-(3 bromo, 2 hydroxy, 4 methyl-phenyl)-2-(4 bromophenyl- sulphanyl)-etanone. Different methods were used, such as chemical elemental analysis, thermal-gravimetry, infrared absorption spectroscopy and electronic spin resonance (ESR). From chemical analysis resulted that the combination ratio ligand-central atom is 2:1. The new compound can also be used for gravimetric determination of Cu(II).

Abstact In the present work voltammetric investigations have been performed on HgCl2 aqueous solutions prepared from a Cz 9024 reagent. Carbon paste electrode (CPE), eriochrome black T modified carbon paste electrode (MCPE/EBT) and KCl 1M as background electrolyte, were involved within the experimental procedures. Cyclic voltammetry (CV) has been performed in order to compare the behaviour of the two electrodes in both K3[Fe(CN)6] and mercury calibration aqueous solution. Differential pulse anodic stripping voltammetry (DPASV) was used to determine the most suitable parameters for mercury determination. All experiments were performed at 25 ± 1 ℃, using an electrochemical cell with three-electrodes connected to an Autolab PG STAT 302N (Metrohm-Autolab) potentiostat that is equipped with Nova 1.11 software. The measured potential values were generated by using the silver chloride electrode (AgClE) as reference and a platinum wire electrode as auxiliary. A series of time depending equations for the pre-concentration and concentration steps were established, with the observation that a higher sensitivity can be obtained while increasing the pre-concentration time. DPASV were drawn using the CPE in 11.16 % coriander, as mercury complex, the voltamograms signals indicating mercury oxidation, with signal intensity increasing in time.

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Abstract Thermal degradation of Teflon was investigated by thermoanalytical methods (TG and DTA). In the kinetic analysis of the experimental data, the NPK method proves to be a valuable tool, allowing for some new kinetic aspects of the degradation process to be obtained. Analysis of the computed isothermal and isoconversional vectors provided some insight into the reaction kinetics. Two different initiation pathways were suggested to control the global degradation kinetics, their relative contribution being temperature-dependant

Abstract The structural NMR and X-ray studies of 6,6’-(Oxybis(4,1- phenylene))bis-(2-allylpyridazin-3(2H)-one), a bis-pyridazine derivative heterocycle, are reported in this study. Both 1H- and 13C- NMR confirm the proposed structure of compound. In order to establish unequivocally the structure of compound, the X-ray data analysis was performed. The compound crystallizes in the triclinic P-1(2) space group with a = 10.3699(7) Å, b = 10.6972(6) Å, c = 11.0449(4) Å, α = 87.941(5)°, β = 75.564(5)°, γ = 72.055(5)°, V= 1127.68 (12) Å3 and Z = 2. Molecular and crystal packing parameters for the novel heterocyclic system were obtained from intensity data collected at room temperature. The two phenyl rings (from the diphenyl ether moiety) are perpendicular one to each other and, on its turn, each phenyl ring is almost coplanar with the pyridazine ring

Abstract This study presents a physicochemical analysis on the orthodox icon “The grieving Mother” from XIXth century. The icon is made by an anonymus painter, in tempera pigments, on a lime wood support, Tillia cordata. God’s Mother is represented from one side, only the bust, with the head down, framed by a white border. The predominant colors of the icon are ultramarine blue, ocher, red-brown, with silver leaf. The edges of the panel were painted with tempera pigments as the border. On the right edge an inscription in blue ink, can be seen, but is unreadable. The painting layer has gaps, fissures, detachments, dirt, degraded and scaly varnish. The panel is made from a single board, transversally cut, without crossbeams. The study is based on the identification of some archeometric characteristics of the wood panel and of the pigment layer. To determin painting materials and the conservation state, Fourier Transform Infrared Spectroscopy (Micro-FTIR) and Scanning Electron Microscope coupled with Energy Dispersive X-ray spectroscopy (SEM-EDX) were employed. Using this methods we identify the pigments used and the state of degradation of the panel. The FTIR spectrum analysis showed that the pigment layer contains schellac varnish, ultramarine blue and dust, a conclusion supported by SEM-EDX analysis.

Abstract : Pollution of high voltage (HV) insulators is a phenomenon with a considerable impact to the performance of transmission and distribution electrical networks. The use of composite materials and especially Silicone Rubber proved to be an efficient improvement, capable of suppressing the problem and diminishing the flashover probability. As a result ceramic insulators in transmission lines are replaced by insulators with composite housing, either HTV Silicone Rubber or LSR. In the case of HV substations however, the replacement of insulators is rather difficult, due to the complexity of the equipment and the corresponding financial cost. In this case the application of RTV Silicone Rubber is an equivalent alternative. The ceramic insulators are covered with a 0.5 mm RTV SIR coating which provides the advantages of composite insulators on a ceramic substrate. After installation the possible material lifetime, which is determined by the service conditions and the material formulation, is of primary concern. In Crete, a large scale application exists and coatings that exceed a service period of 10 years are still in operation. The present study focuses on the structural and morphological characterization of field collected composite insulators of various ages so that the degradation degree can be correlated with their service.

Abstract We report herein a feasible study concerning design, syntheses and structure of some new diazolium salts with dihydroxyacetophenone skeleton of anticipated anticancer and antimicrobial activity. The syntheses of the desired imidazolium dihydroxyacetophenone salts occur smoothly, via an N-alkylation reaction, with good to excellent yields. The structure of the newly compounds were assigned without doubts by elemental and spectral analysis: IR, 1H NMR, 13C NMR, 2D-COSY, 2D-HETCOR (HMQC), long range 2D-HETCOR (HMBC).

Abstract The extreme toxicity of cyanide, its wide industrial application as well as its continued illegal use generate research interest in different fields of science, imposing multidisciplinary approach to study cyanide poisoning. We show here that the reaction between cyanide and ninhydrin can be performed at ambient conditions; however, the ninhydrin reagent has to be freshly prepared in oxygen free solvent. Besides, we show that the reading of the absorbance at 485 nm might be more suitable and reliable than that at 590 nm, where the pH-dependent blue colored cyanide-ninhydrin adduct is less stable. Ninhydrin-based color reagent can be used to quantify the cyanide released from plant seeds. In sodium carbonate medium, the proposed assay is fast, cheap and environmentally friendly