Apparent anisotropy of adhesive bonds with weak adhesion and non-destructive evaluation of interfacial properties.

The present research attempts to non-destructively characterize mechanical properties, which are representative of the interfacial adhesion and bond line cohesion of adhesively bonded assemblies, using an ultrasonic method. Eight bonded samples made of two aluminium substrates and of an epoxy-based adhesive layer were manufactured: four in which the adhesive is fully cured (100%) and four in which crosslinking is partial (80%). For each level of curing, four different surface treatments were applied to the aluminium substrates before assembling, in order to vary the quality of adhesion.

Synthesis of cross-linked epoxy microparticles: effect of the synthesis parameters.

Epoxy crosslinked microparticles were synthesized from the reaction between diglycidyl ether of bisphenol A and a diamino hardener, through precipitation polymerization in a polypropylene glycol solvent. The influence of the monomer concentration, the amine/epoxy stoichiometric ratio, the reaction temperature and the structure of the diamine (aromatic or cycloaliphatic) were investigated, since these parameters may affect the structure and properties of the particles. Morphological analysis revealed that, in all cases, spherical particles were obtained with diameters ranging from 1 to 6 μm.

Structural elucidation of the Bi(2(n + 2))Mo(n)O(6(n + 1)) (n = 3, 4, 5 and 6) family of fluorite superstructures by transmission electron microscopy.

The cationic framework structure of a whole new family of compounds with the general formula Bi(2(n + 2))Mo(n)O(6(n + 1)) (n = 3, 4, 5 and 6) has been elucidated by transmission electron microscopy (TEM) methods. High-resolution transmission electron microscopy (HRTEM) has been used to postulate heavy-atom models based on the known structure of the n = 3 phase, Bi(10)Mo(3)O(24). These models were tested by HRTEM image simulation, electron diffraction and powder X-ray diffraction simulation methods which agreed with the experimental results.

Intense gamma-ray source in the giant-dipole-resonance range driven by 10-TW laser pulses.

A gamma-ray source with an intense component around the giant dipole resonance for photonuclear absorption has been obtained via bremsstrahlung of electron bunches driven by a 10-TW tabletop laser. 3D particle-in-cell simulation proves the achievement of a nonlinear regime leading to efficient acceleration of several sequential electron bunches per each laser pulse. The rate of the gamma-ray yield in the giant dipole resonance region (8 View Article and Find Full Text PDF

Sepiolite-based epoxy nanocomposites: relation between processing, rheology, and morphology.

Rheology of sepiolite-based epoxy suspensions as well as morphology and dynamic mechanical properties of the corresponding nanocomposites are discussed in this paper. The influence of the type of sepiolite used, i.e.

Nanostructured ceramics of 0.92PbZn(1/3)Nb(2/3)O(3)-0.08PbTiO(3) processed by SPS of nanocrystalline powders obtained by mechanosynthesis.

This work reports the successful use of a combination of non-conventional methods of synthesis (mechanosynthesis) and sintering (spark plasma sintering, SPS) for the preparation of nanostructured 0.92PbZn(1/3)Nb(2/3)O(3)-0.08PbTiO(3) (PZN-PT) ceramics.

Relaxor behavior, polarization buildup, and switching in nanostructured 0.92 PbZn1/3Nb2/3O3-0.08 PbTiO3 ceramics.

The relaxor-type behavior, electrical polarization buildup, and switching in 0.92Pb(Zn(1/3)Nb(2/3))O(3)-0.08PbTiO(3) nanostructured ceramics with a grain size of approximately 20 nm is reported for the first time.

Nuclides.net: a computational environment for nuclear data and applications in radioprotection and radioecology.

An interactive multimedia tool, Nuclides.net, has been developed at the Institute for Transuranium Elements. The Nuclides.

Synthesis and antileishmanial activity of 6-mono-substituted and 3,6-di-substituted acridines obtained by acylation of proflavine.

Two new series of diaminoacridinic derivatives obtained from proflavine and N-(6-amino-3-acridinyl)acetamide were synthesised and assessed for their cytotoxic and antileishmanial activities. Two compounds, N-[6-(acetylamino)-3-acridinyl]acetamide and N-[6-(benzoylamino)-3-acridinyl]benzamide demonstrated highly specific antileishmanial properties against the intracellular amastigote form of the parasite. Structure-activity relationships established that the antiproliferative activity against human cells was greatly enhanced by the presence of a benzoylamino group in 6-mono-substituted acridines, while the presence of two acetylamino or benzoylamino groups in 3,6-di-substituted acridines strongly increased the specificity of the molecules for Leishmania parasite, suggesting that symmetric conformations could preferentially interfere with Leishmania metabolism.

Novel tetra-acridine derivatives as dual inhibitors of topoisomerase II and the human proteasome.

Acridine derivatives, such as amsacrine, represent a well known class of multi-targeted anti-cancer agents that generally interfere with DNA synthesis and inhibit topoisomerase II. But in addition, these tricyclic molecules often display secondary effects on other biochemical pathways including protein metabolism. In order to identify novel anti-cancer drugs, we evaluated the mechanism of action of a novel series of bis- and tetra-acridines.

Molecular simulation of the interlayer structure and the mobility of alkyl chains in HDTMA+/montmorillonite hybrids.

Molecular simulation techniques are used to find the basal spacing of organoclay on the basis of the energy minimum, using the canonical NVT ensemble. Then, the interlayer structure and mobility of alkyl chains are explored based on the interlayer atomic density profiles. Besides the basic lateral-monolayer arrangement, lateral-bilayer accompanied by partial a pseudo-trilayer and a transition structure between the two basic lateral models are observed.

(1)H and (13)C chemical shifts for 2-aryl and 2-N-arylamino benzothiazole derivatives.

The (1)H and (13)C NMR resonances for forty-three 2-aryl and 2-N-arylamino benzothiazole derivatives were completely assigned using a concerted application of one- and two-dimensional experiments (DEPT, gs-COSY, gs-HMQC and gs-HMBC).

1H and 13C chemical shifts for acridines: Part XIX. N,N'-diacylproflavine derivatives.

The 1H and 13C NMR resonances of 15 N,N'-diacylproflavines were assigned completely and unequivocally using a concerted application of one- and two-dimensional experiments (DEPT, gs-COSY, gs-HMQC and gs-HMBC).

Influence of cationic surfactant removal on the thermal stability of organoclays.

The microstructure, thermal stability, surface energy, and swelling characteristics of two kinds of commercial organoclays, before and after washing treatment with a mixture of H2O/ethanol, were investigated using X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), wettability measurement, and swelling measurement. This study demonstrates that the external-surface physically adsorbed surfactant can be removed after washing treatment, resulting in an increase in thermal stability and a decrease in surface energy of the resultant organoclays. Organoclays are difficult to be introduced into a solvent when their surface energies are lower than that of the solvent.

Grafting of swelling clay materials with 3-aminopropyltriethoxysilane.

The grafting reaction between a trifunctional silylating agent and two kinds of 2:1 type layered silicates was studied using FTIR, XRD, TGA, and 29Si CP/MAS NMR. XRD patterns clearly indicate the introduction of 3-aminopropyltriethoxysilane (gamma-APS) into the clay interlayer. In the natural montmorillonite, gamma-APS adopts a parallel-bilayer arrangement, while it adopts a parallel-monolayer arrangement in the synthetic fluorohectorite.

New hybrid organic-inorganic nanocomposites based on functional [Ti16O16(OEt)24(OEMA)8] nano-fillers.

New hybrid nanocomposites based on a methacrylate functionalized titanium-oxo cluster as nano-cross-linker show improved mechanical properties, optical transparency and photochromic activity.

Broad energy spectrum of laser-accelerated protons for spallation-related physics.

A beam of MeV protons, accelerated by ultraintense laser-pulse interactions with a thin target foil, is used to investigate nuclear reactions of interest for spallation physics. The laser-generated proton beam is shown (protons were measured) to have a broad energy distribution, which closely resembles the expected energy spectrum of evaporative protons (below 50 MeV) produced in GeV-proton-induced spallation reactions. The protons are used to quantify the distribution of residual radioisotopes produced in a representative spallation target (Pb), and the results are compared with calculated predictions based on spectra modeled with nuclear Monte Carlo codes.

Activity of benzothiazoles and chemical derivatives on Plasmodium falciparum.

Malaria is a major health concern particularly in Africa which has about 90% of the worldwide annual clinical cases. The increasing number of drug-resistant Plasmodium falciparum justifies the search for new drugs in this field. Antimalarial activity of 2-substituted 6-nitro- and 6-amino-benzothiazoles and their anthranilic acids has been tested.

Synthesis and antileishmanial activity of (1,3-benzothiazol-2-yl) amino-9-(10H)-acridinone derivatives.

(1,3-Benzothiazol-2-yl) amino-9-(10H)-acridinone derivatives were synthesized via a procedure based on the Ullman reaction and were assessed for their in vitro antileishmanial and anti-HIV activities. Two derivatives, 4-(6-nitro-benzothiazol-2-ylamino)-10H-acridin-9-one and 1-(6-amino-benzothiazol-2-ylamino)-10H-acridin-9-one, revealed a selective antileishmanial activity, mainly due to amastigote-specific toxicity. Results suggested that:the addition of a benzothiazole group on a parent amino-9-(10H)-acridinone ring could enhance antileishmanial abilities, the presence of a 6-amino-benzothiazole group on position 2 amino chain or a 6-nitro-benzothiazole group on position 4 amino chain was essential for specific anti-amastigote properties.

Tetrahydroacridin-9-ones, 9-chlorotetrahydroacridines, 9-amino-tetrahydroacridines and 9-(pyrazol-1-yl)-tetrahydroacridines derived from chiral cyclanones.

A series of tetrahydroacridines related to tacrine have been synthesized starting from 3-methylcyclohexananone, menthone, pulegone, carvone and dihydrocarvone (both racemic and chiral). In many cases, the yields and purity of the compounds have been improved by the use of a microwave oven. These compounds have been characterized by (1)H and (13)C NMR data.

Characterization of ammonium chloride derivatives by salt clustering in electrospray mass spectrometry.

Clustering of ammonium chloride salts was studied using an electrospray source to characterize the form, mono- vs. dihydrochloride, of organic compounds by mass spectrometry. This new way of taking advantage of cluster formation is applied to aminomethylacridines as their storage requires the synthesis of such derivatives.

A reversible copper extrusion-insertion electrode for rechargeable Li batteries.

Although widely used, the most promising Li-based technologies still suffer from a lack of suitable electrodes. There is therefore a need to seek new materials concepts to satisfy the increasing demands for energy storage worldwide. Here we report on a new layered electrode material, Cu(2.

A new aquahydroxidocopper(II) oxovanadium(IV) vanadate, Cu(H2O)(OH)VO(VO4).

Single crystals of the title compound have been prepared hydrothermally. Vanadate tetrahedra and distorted oxovanadium octahedra form layers, linked by two independent Cu atoms located on inversion centres. Each Cu atom is surrounded by six O atoms, forming an octahedron distorted by Jahn-Teller elongation.

In vitro activities of 7-substituted 9-chloro and 9-amino-2-methoxyacridines and their bis- and tetra-acridine complexes against Leishmania infantum.

9-Chloro and 9-amino-2-methoxyacridines bearing different substituents in position 7, as well as their corresponding unsubstituted dimeric and tetrameric complexes, were investigated for in vitro antiproliferative properties against Leishmania infantum compared to toxicity towards human monocytes. The results clearly confirmed that several compounds of the 2-methoxyacridine series, together with their corresponding dimeric and tetrameric derivatives, had strong in vitro antiparasitic properties. Antileishmanial activity was shown to depend on the nature of both 7- and 9-substituted groups in monoacridines, while it varied according to the nature of the 9-substituted group and the length of the linker among bis- and tetra-acridines.

CH3CN: X-ray structural investigation of a unique single crystal. beta --> alpha phase transition and crystal structure.

The phase transition from the low- (beta) to the high-temperature (alpha) form of acetonitrile, CH(3)CN, has been directly observed and studied on a unique single crystal. Both the beta and alpha structures have been determined at temperatures close to the transition temperature (206 K and 201 K), taking advantage of the hysteresis. A single crystal of the beta form was obtained for the first time.