R Nabizadeh , A. H Mahvi , S. K Ghadiri , S Nasseri , A Mesdaghinia, A Abouee ,
Volume 4, Issue 3 (Autumn2012 2012)
Abstract
Abstract Background & Objectives: This study evaluated the ability of natural clinoptilolite zeolite in form of Surfactant Modified Zeolites (SMZS) in removal of methyl tert-butyl ether (MTBE) from water using batch tests. Direct comparison between none modified zeolite (NMZ) and Surfactant-Modified Zeolites (SMZ) was made for MTBE removal from water. Materials & Methods: The two Clinoptilolite samples used in this study were obtained from Semnan and Meyaneh province. Before the synthesis of the surfactant modified zeolites, the two kinds of zeolites were milled and sieved in to two sizes ranging 0.21-0.25mm (60 to 70Mesh) as fine and 0.59-0.84mm (20 to 30Mesh) as coarse. Total cation exchange capacity (CEC) and the external CEC (ECEC) of zeolites were measured and the best zeolite according to CEC & ECE for rest of the examinations was selected. Results: Results of this study showed that adsorption capacity of the zeolites will be remarkably improved toward MTBE molecules by modification of its surface by surfactants like Hexa Decyl Trimethyl Ammonium-Chloride (HDTMA-CL) & n-Cetyl Pyridinium Bromide (CPB). Especially the HDTMA had more effective performance and could receive to average adsorption capacity of 13.02 mg/g and average removal efficiency of 65.11 percent by the initial MTBE concentration of 10 mg/L. Conclusion: According to the results of this study SMZ are suitable candidate for removal of MTBE molecules from contaminated solutions
Karim Abdolmohammadi, Farhad Ghadiri Sourman Abadi, Hamid Alizadeh, Rogeyeh Khodaei, Sanaz Norouzi,
Volume 11, Issue 2 (10-2019)
Abstract
Introduction: Executive functions refer to the use of cognitive processes to control thoughts and emotions. The purpose of this study was to compare the executive functions in premature and normal children.
Methods: The present study is a causal comparative study. The statistical population of this study was Tabriz Premature Children that 30 of these children were selected by using available sampling and compared with 30 normal children. Participants responded to the Behavioral Rating Inventory of Executive Functions (BRIEF). Data were analyzed using analysis of multivariate variance.
Results: The results showed that there is a significant difference between the mean components of vulnerability (inhibition, shift of attention, emotional control, initiation, work memory, organization) and total score of executive functions
Conclusions: Preterm children have weakness in terms of executive functions than normal children that the cause of this problem is the greater vulnerability of the central nervous system due to the early birth and educational problems of these children.
