introduction: the aim of this study was to compare the chemical compounds of white proroot mineral trioxide aggregate (wmta) hydrated at different ph environments. methods and materials: mixed samples of wmta were kept in acidic (ph=5.4), neutral (ph=7.4) and alkaline (ph=9.4) environments for 48 h. then, x-ray diffraction (xrd) analysis was performed for both hydrated and powder forms of wmta....

raw cane sugar is one of the most important product in the sugar industry and is the main raw material for the white sugar production. morphological and physical properties of this product might influence the final white sugar. for instance, the behavior during centrifugation, transport and storage is related to the characteristics of these crystals. the object of this study was to determine th...

Crystal size distribution (CSD) in metamorphic rocks provide fundamental information about crystal nucleation and growth rate, growth time and the degree of overstepping. CSD data for garnet, staurolite, kyanite and andalusite crystals from the aureole demonstrate that the earliest formed of these minerals, garnet, has the highest population density and the shortest growth time. The last formed...

Time-series hydrothermal syntheses from two organic-cation-free gels with different compositions were employed to study the factors that control the final size of zeolite L crystals. The first gel had a starting K/Al ratio of 10, whereas in the second one it was three times lower. The relatively simple chemical composition of the starting gels and the combination of complementary characterizati...

In this paper, design and construction of a tactile sensor for measuring contact-force is presented. Mechanism of measuring contact-force in this tactile sensor is based on impedance changing of piezoelectric crystal and voltage of different points in circuit as a result of applying force on the crystal. By considering a specific point in the circuit and recording the changes of its voltage, ma...

The perovskite-type oxides strontium-substituted lanthanum nickelate (LSNO) were prepared by a coprecipitation method in the present of octanoic acid as surfactant. The phase composition, morphology,lattice parameters and size of nanoparticles in these materials were characterized through Fourier transform infr...

Abstract In this work hydrothermal synthesis of zeolite NaA crystals with a composition of Al2O3:aSiO2:bNa2O:cH2O was investigated. Effects of SiO2/Al2O3, Na2O/Al2O3 and H2O/Al2O3 ratios and crystallization temperature and time were studied on crystallinity and crystal size of zeolite NaA crystals. It was tried to understand the interactions between these parameters. The crystal species o...