Showing 4 results for M. Fazli
M. J. Tafreshi1, M. Fazli2,
Volume 6, Issue 2 (Spring 2009 2009)
Abstract
Abstract:
fabricated. Modifications carried out in different parts of the old system in order to control most
of the growth parameters with more accuracy. The fabricated system was used to grow sapphire
single crystals with almost 10 mm in diameter and 50 mm in length. The crystallinity and
structure of the grown crystals were characterized by computer aided single crystal X-ray
diffraction technique.
A Verneuil system, more sophisticated than a conventional one, has been designed and
M. J. Tafreshi, B. Dibaie, M. Fazli, M. Alidaie,
Volume 8, Issue 1 (winter 2011 2011)
Abstract
A. Allahverdi, E. Najafi Kani, M. Fazlinejhad,
Volume 8, Issue 4 (december 2011)
Abstract
Abstract: The linear expansion, early-age compressive strength and setting times of the binary mixtures of gypsum and Portland cement clinkers of relatively low C3A-contents were investigated. For this reason, type 1, 2, and 5 of Portland cement-clinkers were selected and a number of binary mixtures were designed. At relatively lower percentages of gypsum (about 5%), the early strength behavior is improved. Results obtained for compressive strength of mixtures with 5% gypsum confirm the possibility of achieving 28- and 90-day compressive strengths up to values higher than 100 MPa and 130 MPa, respectively. At relatively higher percentages of gypsum (more than 25%), excessive expansion caused by ettringite formation results in the formation of micro-cracks effectively weakening the strength behavior. The work suggests that type S expansive cements could be produced from Portland cement clinkers of relatively low C3Acontents.
M. J. Tafreshi, B. Dibaie, M. Fazli,
Volume 9, Issue 1 (march 2012 2012)
Abstract
Abstract: A thermodynamic model was used to find out the optimum temperature for the growth of ZnS single crystals in closed ampoules by chemical vapor transport technique. Based on this model 1002 °C was found to be optimum temperature for 2 mg/cm3 concentration of transporting agent (iodine). ZnS Crystals were grown in optimum (1002 °C) and non-optimum (902 °C and 1102 °C) temperatures. The composition structure and microstructure of the grown crystals were studied by Atomic absorption spectroscopy, X-ray diffraction and Scanning electron microscopy measurements. Properties of the grown crystals were correlated to the growth conditions especially a stability in mass transport along the closed tube length.
