Thermodynamics of Mixtures Excess Volumes and Energies of Mixing of Cycloalkane Mixtures (Cyclopentane to Cyclooctane)

The volumes of mixing for the systems cyclopentane + cyclohexane, cyclopentane + cycloheptane, cyclohexane + cycloheptane (at 20°C), and cyclopentane + cyclooctane, cyclohexane + cyclooctane, cycloheptane + cyclooctane (at 30 °C) have been measured with a dilatometer. All systems show volume contractions, except the first. The energies of mixing are also given. They vary from 7 to 55 J/mol for equimolar solutions.     

Chloro(η6‐p‐cymene)(2‐methyl‐5‐oxo‐7‐phenyl‐5,6‐di­hydro‐2H‐1,2,4‐triaz­epine‐3‐thiol­ato‐κ2N4,S)­ruthenium(II)

The novel title ruthenium(II) complex, [RuCl(C₁₀H₁₄)(C₁₀H₁₀N₃OS)], was synthesized from the reaction of 1,2,4‐triazepine, a new class of bidentate ligands, with [Ru(p‐cymene)Cl₂]₂. The 1,2,4‐triazepine ligand is coordinated to the metal centre through the N‐4 and S atoms, forming a four‐membered chelate ring. This is the first structural example of a transition metal complex containing a 1,2,4‐triazepine ligand.     

Reactivite du Bis(dichlorophosphoryl)imide Vis a Vis de La N,N-Bis(2-chloroéthyl)-amine Application a la Synthese de Molecules Susceptibles de Presenter une Activite Antitumorale

The reaction of bis(dichlorophosphoryl)imide HN(P(O)Cl 2 ) 2 1 , with N,N-bis(2-chloroethyl)amine HN(CH 2 CH 2 Cl) 2 (bCEA), has been studied in order to synthesize Phosphorus-Nitrogen derivatives which present anti-tumoral activity. It has been possible to show the formation of the mono 2 , di 3 and tetrasubstituted 4 derivatives as well as the existence of diastereoisomers for 2 and 3 . The combined use of NMR ( 31 P, 13 C) and mass spectrometry has allowed us to show the instability of the tetrasubstituted derivative wich is transformed to the O-alkylated compound 4a with elimination of HCl. We studied also the cosubstitution reactions of 1 by HN(CH 2 CH 2 Cl) 2 and ammonia on the one hand, HN(CH 2 CH 2 Cl) 2 and glycine ethyl ester on the other hand. Spectroscopic studies of the resulting products revealed the involvement of N-alkylation reactions leading to 6 and 7 . The study of the antitumoral activity of these compounds was undertaken. Only the phosphazene derivative 2 which contains a bifunctionnal alkylating agent exhibited a moderate anti-tumoral activity.     

Spin-coating deposition of PbS and CdS thin films for solar cell application

In this work, we describe a simple spin-coating deposition technique for lead sulphide (PbS) and cadmium sulphide (CdS) films from a methanolic metal–thiourea complex. The characterization of the films by X-ray diffraction and X-ray photoelectron spectroscopy techniques revealed that pure cubic phase PbS and CdS layers were formed via this method. As shown by atomic force microscopy and scanning electron microscopy results, both films were homogeneous and presented a smooth surface. Optical properties showed that the energy band gap of PbS and CdS films were around 1.65 and 2.5 eV, respectively. The PbS film is p-type in nature with an electrical conductivity of around 0.8 S/cm. The hole concentration and mobility were 2.35 × 10¹⁸ cm^?3 and 2.16 × 10^?3 cm²/V/s, respectively, as determined from Hall measurement. Both films were used to develop a thin film solar cell device of graphite/PbS/CdS/ITO/glass. Device characterization showed the power conversion efficiency of around 0.24 %. The corresponding open circuit voltage, short circuit current and fill factor were 0.570 V, 1.32 mA/cm² and 0.32, respectively.     

Experimental determination and prediction of (solid + liquid) phase equilibria for binary mixtures of aromatic and fatty acids methyl esters

Solid–liquid equilibria for binary mixtures of {methyl stearate (1) + biphenyl (2)}, {methyl stearate (1) + naphthalene (2)}, {methyl palmitate (1) + biphenyl (2)} and {methyl palmitate (1) + naphthalene (2)} were measured using differential scanning calorimeter. Simple eutectic behaviours for these systems were observed. The experimental results were correlated by means of the NRTL, Wilson, UNIQUAC and ideal models. The root-mean-square deviations of the solubility temperatures for all measured data vary from 0.5477 K (for UNIQUAC model) to 7.79 K; the deviations depend on the binary system studied and particular model used. The best solubility correlation was obtained with UNIQUAC model and this observation confirms previous results.     

Applied multi-pulsed laser in surface treatment and numerical-experimental analysis

This paper presents a comparison between simulation and experimental results of the melting process of metallic material by a pulsed laser source Nd-YAG. The simulations of temperature and velocity fields of melted material were done by solving the transient heat transfer and fluid-flow equations. Variations of the thermophysical properties were considered. Furthermore, the model included the effects of the surface-tension gradient on the fluid surface and the buoyancy force. The simulation was useful in improving our understanding of the phenomena occurring in the treated material. Using a laser triangulation sensor, an experimental study was also conducted on the surface profile of the melted zones to seek a relationship between the so-called keyhole effect and the laser triangulation measurements. The keyhole effect induced strong surface deformations and often formed cavities, which were undesirable in the surface treatment process. The laser power, energy density, and treatment duration could be optimized to prevent the keyhole effect. The predicted laser melted zone (LMZ) morphology was in good agreement with the corresponding experimental measurements for various irradiation conditions, as long as the keyhole effect did not occur.     

Performance comparison with different methods for ethanol/O2 biofuel cell based on NAD+ cofactor immobilized and activated by two types of carbon nanoparticles

Journal of Solid State Electrochemistry - Biofuel cells are an attractive alternative to conventional fuel cells, because they use biological catalysts. We report in this article the construction...     

Competitive adsorption of anionic dyes onto DMOA modified MCM-41

Research on Chemical Intermediates - The single and binary adsorption of two anionic dyes Acid Yellow 17 (AY17) and Naphtol Green B (NGB) onto N–N–Dimethyl-n-octylamine (DMOA) modified...