Complex 3D macrostructured nanoparticles are transformed from amorphous silica into pure polycrystalline α-quartz using catalytic quantities of alkaline earth metals as devitrifying agent. Walls as thin as 10 nm could be crystallized without losing the architecture of the particles. The roles of cation size and the mol% of the incorporated devitrifying agent in crystallization behavior are stud...

Silica (SiO2) is one of the most common materials on Earth. The crystalline form α-quartz is the stable silica polymorph at ambient conditions although metastable forms exist. α-quartz is a piezoelectric material, it can be produced artificially and is widely used for example in electronics and the biosciences. Despite the many application areas, the atomic surface structures of silica polymorp...

Background: Achillea tenuifolia Lam. (Compositae) with small yellow flowers and several times pinnately divided leaves in worm shape is known for many years in the folk medicine. It has been used to reduce sweating and to stop bleeding. It helps regulation of the menstrual cycle and reduces heavy bleeding and pain. Materials and Methods: Plant material (flower, leaf and stem) was collected in...

We demonstrate mid-infrared second-harmonic generation as a highly sensitive phonon spectroscopy technique that we exemplify using α-quartz (SiO2) as a model system. A mid-infrared free-electron laser provides direct access to optical phonon resonances ranging from 350 cm−1 to 1400 cm−1. While the extremely wide tunability and high peak fields of an free-electron laser promote nonlinear spectro...

in this paper, synthesis of the flower-like zinc oxide was performed using microwave assisted dicationic ionic liquid [mmp(im)2 ]br2 . the polycrystalline flower-like zinc oxide nanostructure was obtained when a suitable mole ratio (ionic liquid /zinc acetate) and short duration microwave was used. x-ray diffraction (xrd), scanning electron microscopy (sem), and photoluminescence (pl) spectra w...

Linear variations between specific heat Cp and thermal expansion αp, and between αp and isothermal compressibility κT (Pippard relations) are verified for the α−β transition in quartz. By analyzing the observed data for Cp, αp and κT the critical behavior of the α−β transition in this crystal is investigated. Also, by analyzing the experimental Cp data in the vicinity of Tc(=849.2 K) using a po...

Water scarcity and salinity are important limitations for saffron (Crocus sativus L.) production in arid and semi-arid regions. The purpose of this research was to study the interaction effects of water salinity and deficit irrigation on the macroscopic water extraction model for saffron. The effect of salinity and water stress on root-water uptake coefficient was determined by additive and mul...

background: achillea tenuifolia lam. (compositae) with small yellow flowers and several times pinnately divided leaves in worm shape is known for many years in the folk medicine. it has been used to reduce sweating and to stop bleeding. it helps regulation of the menstrual cycle and reduces heavy bleeding and pain. materials and methods: plant material (flower, leaf and stem) was collected in k...

The polymerization of laminin into a cell-associated network--a key step in basement membrane assembly--is mediated by the laminin amino-terminal (LN) domains at the tips of the three short arms of the laminin αβγ-heterotrimer. The crystal structure of a laminin α5LN-LE1-2 fragment shows that the LN domain is a β-jelly roll with several elaborate insertions that is attached like a flower head t...