Alkaline solutions, such as sodium, potassium or lithium silicates, appear to be very promising as healing agents for the development of encapsulated self-healing concretes. However, the evolution of their mechanical and acoustic properties in time has not yet been completely clarified, especially regarding their behavior and related kinetics when they are used in the form of a thin layer in co...

Bond paths of maximum electron density spanning O-O edges shared between equivalent or quasiequivalent MOn (n > 4) coordination polyhedra are not uncommon electron density features displayed by silicates. On the basis of the positive values for the local electronic energy density, H(rc), at the bond critical points, rc, they qualify as weak "closed-shell" interactions. As observed for M-O bonde...

The most abundant matrix minerals in chondritic meteorites—hydrated phyllosilicates and ferrous olivine crystals—formed predominantly in asteroids during fluid-assisted metamorphism. We infer that they formed from minerals present in three less altered carbonaceous chondrites that have silicate matrices composed largely of micrometerand nanometer-sized grains of crystalline forsterite Mg2SiO4 a...

in the present study, the interactions of three different lithium species li+, li3+ and ch3li with several different sites of the most stable tautomers of dna nucleo-bases are presented. this investigation is based on the results of thermochemical properties, quantum theory of atoms in molecules (qtaim) and natural bond orbital (nbo) analysis, obtained at b3lyp/6-311++g(d,p) level of theory. th...

These experiments examined the effects of pre-test intra dorsal hippocampus (intra-CA1) administration of GABAA receptor agonist and antagonist, muscimol and bicuculline respectively, on state-dependent learning induced by lithium. Male NMRI mice were trained in a one-trial step-down inhibitory avoidance task, and immediately after training they received IP injections of either saline (10 mL/kg...

Carbonatites are mantle-derived, intraplate magmas that provide a means of documenting isotopic variations of the Earth's mantle through time. To investigate the secular Li isotopic evolution of the mantle and to test whether Li isotopes document systematic recycling of material processed at or near the Earth's surface into the mantle, we analyzed the Li isotopic compositions of carbonatites an...

Lithio-marsturite, ideally LiCa(2)Mn(2)Si(5)O(14)(OH), is a member of the pectolite-pyroxene series of pyroxenoids (hydro-pyroxenoids) and belongs to the rhodonite group. A previous structure determination of this mineral based on triclinic symmetry in space group P[Formula: see text] by Peacor et al. [Am. Mineral. (1990), 75, 409-414] converged with R = 0.18 without reporting any information o...

Objectives. This study evaluated the influence of cavity surface finishing with diamond burs of different grit mounted on high-speed turbine and ultrasound on the roughness and microshear bond strength (MBS) of a lithium silicate glass-ceramic to enamel and dentin. Methods. Enamel and dentin specimens were divided into seven groups, according to the type of surface finishing: 1200-grit sandpape...

The mixed valence europium nitridosilicate Eu(2)SiN(3) has been synthesized at 900 degrees C in welded tantalum ampules starting from europium and silicon diimide Si(NH)(2) in a lithium flux. The structure of the black material has been determined by single-crystal X-ray diffraction analysis (Cmca (no. 64), a = 542.3(11) pm, b = 1061.0(2) pm, c = 1162.9(2) pm, Z = 8, 767 independent reflections...

The densities of thirteen silicate liquids along the NaZSiOs-TiOz and CaSiOs-TiOZ joins and six other titanium-bung silicate liquids of the general formula X ;$,TiSiO, (where X = Li, Na, K, Rb, Cs, Ca, Sr, Ba) have been measured in equilibrium with air using the double Pt bob Archimedean method. The NazSiOj-TiOz join was investigated from lo-50 mole% Ti02 in the temperature range lOOOI 150°C wh...