Interpretation of micromechanical measurements on butyl acrylate,vinyl acetate based systems: Role of interfaces in “polymer-polymer composites”

Films were obtained by coalescence of different types of latex particles; the purpose of this work was to get informations on the geometric arrangement (so called “morphology”) of the different phases and on the role of interfaces. Such informations are difficult to get by direct investigations (weak contrast in Transmission Electron Microscopy, poor information provided by X-ray measurements on amorphous polymers …) the analysis of experimental data obtained in high resolution mechanical spectrometry appears powerful: it is possible, for instance, to estimate the profile gradient of composition at the interface. Comparison is made between the morphology of the different phases in some films and the correspondent structure of particles.     

Growth Processes and Properties of Fe- and Co Electrodeposited Alumite Films

Growth processes, structure and properties of Fe, Co, FeCo deposited alumite films have been investigated. It is shown that the magnetic characteristics depends both on alumite film parameters and properties of deposited metal (alloy) particles.     

Thermal Hysteresis Accompanying Incommensurate-Commensurate Phase Transition in Mixed Crystals (K1-xCsx)2ZnCl4

The mixed crystal (K_1-xCs_x)₂ZnCl₄ with x = 0, 0.001, 0.01, 0.1, and 0.2 with optical quality has been grown by the Czochralski method. Using the Atomic Absorption Spectroscopy (AAS) and Energy Dispersive Spectroscopy (EDS), we determined the amount of Cs ion included in the mixed crystal. By using of DTA and DSC, we observed the change of T_c and T_i. The thermal hysteresis in the dielectric constants show strong dependence on the thermal process and on the amount of impurity which are explained by the influence of the thermal process and impurity, respectively on the creation, annihilation, and growth of discommensuration (DC).     

Neutron Scattering Techniques and Complementary Methods for Structural and Functional Studies of Biological Macromolecules and Large Macromolecular Complexes

Crystallography Reports - The review describes the application of small-angle scattering (SAS) of neutrons and complementary methods to study the structures of biomacromolecules. Here we cover SAS...     

Conformation of simple aromatic molecules

The conformation of five aromatic molecules were calculated using the atom-atom potentials method. The deformations of valency angles were not considered, and the conformations of some molecules were determined solely by the minimum interaction energy between non-bounded pairs of atoms. In case of molecules having π-bonds, the geometry of the isolated molecule was determined by the balance between the π-electron and the non-bonded energies. A comparison is made between the structure of molecules in the crystal form and the structure of the free molecules determined by conformational analysis. For terphenyl molecule which has different structures in the different phases, a calculation of the structure of molecule in crystal from was done theoretically using lattice energy minimization. Good agreement was found between structures obtained theoretically and experimentally.     

Movement of dopants in redox reaction of electro-conductive polymers

Polypyrrole, formed in an organic solvent, shows higher density and better quality in electrical conductivity and mechanical strength than that formed in water. On electrochemical reduction in an aqueous system the laurylsulfate anion, used as dopant, sticks to the polymer. During reduction a cation moves into the polymer and on oxidation it leaves the polymer. The anion, however, leaves the polymer on reduction in an organic solvent system and cannot penetrate into the polymer on re-oxidation. The redox reaction in the aqueous system reveals a surface reaction process, while the reaction in the organic solvent system undergoes a diffusion-controlled process. This penomenon is consistant with the results of the ion concentration profile.     

Chondroitin Sulfate Protects the Liver in an Experimental Model of Extra-Hepatic Cholestasis Induced by Common Bile Duct Ligation

During liver fibrogenesis, there is an imbalance between regeneration and wound healing. The current treatment is the withdrawal of the causing agent; thus, investigation of new and effective treatments is important. Studies have highlighted the action of chondroitin sulfate (CS) in different cells; thus, our aim was to analyze its effect on an experimental model of bile duct ligation (BDL). Adult Wistar rats were subjected to BDL and treated with CS for 7, 14, 21, or 28 days intraperitoneally. We performed histomorphometric analyses on Picrosirius-stained liver sections. Cell death was analyzed according to caspase-3 and cathepsin B activity and using a TUNEL assay. Regeneration was evaluated using PCNA immunohistochemistry. BDL led to increased collagen content with corresponding decreased liver parenchyma. CS treatment reduced total collagen and increased parenchyma content after 21 and 28 days. The treatment also promoted changes in the hepatic collagen type III/I ratio. Furthermore, it was observed that CS treatment reduced caspase-3 activity and the percentage of TUNEL-positive cells after 14 days and cathepsin B activity only after 28 days. The regeneration increased after 14, 21, and 28 days of CS treatment. In conclusion, our study showed a promising hepatoprotective action of CS in fibrogenesis induced by BDL.     

Crystal Structure and Computational Study of 5-Ethyl-4-(4-Methoxyphenethyl)-4,5-Dihydro-3H-1,2,4-Triazol-3-One and 4-(4-Methoxyphenethyl)-5-Propyl-4,5-Dihydro-3H-1,2,4-Triazol-3-One

Crystallography Reports - Molecular structures of compounds 5-ethyl-4-(4-methoxyphenethyl)-4,5-dihydro-3H-1,2,4-triazol-3-one, (C13H17N3O2) (I) and...     

A Sm(III) Coordination Polymer Containing 2,5-Furandicarboxylic Acid: Crystal Structure and Recognition of Oxalate in Water

Crystallography Reports - The {[Sm2(FDC)2](FDC) · 10H2O}n complex, where H2FDC is a 2,5-furandicarboxylic acid, has been prepared by hydrothermal reaction and structurally characterized by...     

Mechanical Properties of Diamond-Like Silicon–Carbon Films Doped with Vanadium

Crystallography Reports - The influence of doping with vanadium on the mechanical properties of nanocomposite films deposited on silicon substrates has been investigated. It is found that the...