ABSTRACT
Background: The role of preschool administrators in raising children is increasing day by day, so the purpose of this study was to detect the validity and reliability of the professional competency questionnaire and its psychometric assessment in preschool administrators. Methods: This descriptive study was conducted on 380 preschool administrators with a minimum age of 25 and a maximum of 65 year participated in 2018. The sampling method was stratified from four regions of north, south, west and east of Tehran, Iran. Rosenberg self-esteem questionnaire was used for convergent validity. Cronbach's alpha coefficient was used to examine the internal consistency. Face validity, content validity and structural validity were also calculated. The data collection tool was a researcher-made questionnaire. Results: The questionnaire of professional competency of preschool administrators was appropriate in terms of face validity. Indicators related to content validity were appropriate in terms of relevance, transparency and necessity in this study. Cronbach's alpha coefficient was 0.98. The correlation between the total score of the managers' professional competency test and self-esteem was equal to 0.08 with a significance level of 0.58. Conclusion: The professional competency questionnaire of preschool administrators had good validity and reliability to assess the level of professional competency of preschool administrators. Researchers can use this questionnaire to assess the professional competency of preschool administrators.
ABSTRACT
[This corrects the article DOI: 10.1039/C9RA04739E.].
ABSTRACT
Herein, the nanosized ZSM-5 zeolite was synthesized based on a fractional factorial experimental design by a hydrothermal method to study the optimum conditions for the synthesis and formation of the ZSM-5 zeolite by employing different conditions. The samples were synthesized without any organic template, and different conditions, such as the molar composition of the synthesis gel and reaction time, were applied in a wide range. Then, the samples were analysed by X-ray diffraction to investigate the formation of the zeolite ZSM-5, and the results were compared to obtain the optimum conditions for its synthesis. The obtained samples were characterized by SEM, FTIR spectroscopy and TGA. Then, the functionalization of nano zeolite ZSM-5 crystals with ß-cyclodextrin (ß-CD) was investigated. The zeolite surface was first functionalized with amino groups using an amino alkoxysilane. Then, toluene diisocyanate was reacted with the amino-terminated ZSM-5 zeolite crystals and used for the incorporation of ß-CD via its remaining isocyanate groups. After this, a drug delivery system (DDS) was prepared based on the cyclodextrin-modified zeolite with the curcumin anticancer drug, and its formation was studied under experimental conditions. The results of in vitro studies show that this drug delivery system has better characteristics than free curcumin in terms of stability and anti-proliferative and anti-inflammatory effects.
ABSTRACT
Evaluation of porosity type of zeolites is one of the critical topics in catalysis science. The relationship between external surface area and diffuse reflectance (DR) spectra in the near-infrared spectral region has been employed to propose a method for estimation of micro or mesoporosity in ZSM-5 zeolite samples. Linear discriminant analysis (LDA) was utilized to estimate degree of porosity based on near-infrared diffuse reflectance spectra. The textural properties (surface area and pore volume) of micro and mesoporous ZSM-5 samples were measured using N2 adsorption/desorption technique at 77 K and external surface area was calculated by t-plot as a reference method in this work. Several porous ZSM-5 samples with only microporous channels or mesoporous besides them were classified in terms of external surface area and meso pore volume derived from t-plot as "Micro" or "Micro + Meso" type samples. It was concluded that LDA using the PCA for feature selection is capable of generalization and could precisely predict the type of porosity in ZSM-5 zeolites.
