Islamic Azad University North Tehran Branch

About: Islamic Azad University North Tehran Branch is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Adsorption & Catalysis. The organization has 868 authors who have published 968 publications receiving 9987 citations.

Critical Thinking in Personal Narrative and Reflective Journal Writings by In-service EFL Teachers in Iran: Assessment of Reflective Writing

Abstract: Recently, there is a need for fostering the critical reflective side of L2 teacher education. This study investigated the implications of personal narrative (PN) and reflective journal (RJ) writing for Iranian EFL teachers’ reflective writing. Sixty (36 women and 24 men) in-service secondary school EFL teachers were selected based on the convenience sampling from Iran. L2 teachers equally divided into PN and RJ writing groups were provided with particular short stories. L2 teachers in the PN writing group engendered PN writings in response to themes of stories; however, L2 teachers in the RJ writing group had to write their reflections on stories in RJ writings. Hatton and Smith’s (1995) framework was used for the content analysis of data. The quantitative analysis indicated that PN writings were lengthier than RJ writings. Also, there was a statistically significant difference between mean ranks of descriptive and critical reflection writing types signified in PN and RJ writings. However, no statistically significant difference was observed between mean ranks of descriptive reflection and dialogic reflection writing types. Moreover, PN and RJ writings were more descriptive, less descriptive reflective, less and less dialogic reflective, and still less critical reflective. The qualitative analysis revealed that EFL teachers’ PN and RJ writings enjoyed dialogicity. Despite their unwillingness to express voice, findings indicated that Iranian English teachers adopted a more critical perspective through generating PN writings than via engendering RJ writings. In general, the English language teacher education domain in Iran needs a thinking renewal to foster critical L2 teaching.

Polyhydroxybutyrate Production from Natural Gas in A Bubble Column Bioreactor: Simulation Using COMSOL

Abstract: In this study, the simulation of microorganism ability for the production of poly-β-hydroxybutyrate (PHB) from natural gas (as a carbon source) was carried out. Based on the Taguchi algorithm, the optimum situations for PHB production from natural gas in the columnar bubble reactor with 30 cm length and 1.5 cm diameter at a temperature of 32 °C was evaluated. So, the volume ratio of air to methane of 50:50 was calculated. The simulation was carried out by COMSOL software with two-dimensional symmetric mode. Mass transfer, momentum, density-time, and density-place were investigated. The maximum production of biomass concentration reached was 1.63 g/L, which shows a 10% difference in contrast to the number of experimental results. Furthermore, the consequence of inlet gas rate on concentration and gas hold up was investigated Andres the simulation results were confirmed to experimental results with less than 20% error.

Estimation of Doppler Curve for LEO Satellites

Abstract: Doppler frequency shift which is defined as “the observed changes in frequency of transmitted waves when relative motion exists between the source of waves and an observer”, has wide applications in science, technology and different industries including communications, medicine, aerospace, electronics and etc. One of its common applications in aerospace is its use in tracking satellites and orbit determination. In low earth orbiting satellites, because of their low altitude to earth and their high rotation period around it, Doppler shift is appropriate to be used for tracking. In this paper, satellite distance and its derivative in time which is parameter in obtaining Doppler shift is derived. Position of the satellite is firstly derived using equations governing on them and TLE which contains orbital elements and essential information in different coordinate systems such as ECI, ECEF and topocentric. Then satellite distance to ground station and its changes in time is calculated via transformations of coordinate systems to each other. Having the distance, its derivative and beacon signal frequency, Doppler curve can be estimated in each pass of the satellite. Doppler shift can be used in an appropriate and precise satellite tracking technique.

Production of Vitamins B3, B6 and B9 by Lactobacillus Isolated from Traditional Yogurt Samples from 3 Cities in Iran, Winter 2016

Abstract: Background and Objective: B-group vitamins have important roles in many aspects of cellular metabolism and humans cannot synthesize them. So, they should be obtained from external resources. This project provides a new insight into assessing the production of vitamins B3, B6 and B9 by Lactobacillus, isolated from traditional yogurt samples from 3 different cities of Iran; Golpayegan, Sanandaj and Tehran (Damavand). Material and Methods: Following 72 h of anaerobic culture of the Lactic acid bacteria at 37°C in 5% CO 2 , some Lactobacillus species from traditional yogurt samples were isolated and characterized both morphologically and biochemically. Isolates were identified following 16S rRNA PCR-amplification and sequencing. Including Lactobacillus (L.) ozensis strain Gon2-7, L. acidophilus strain KU, L. helveticus strain D76, L. helveticus strain Dpc 4571, L. fermentum strain 1, L. rossiae strain DSM15814T, L. casei strain NCDO, L. delbrueckii strain ATCC 11842, L. crispatus strain MRS 54.4, L. delbrueckii strain SB3 and L. paracasei subsp. tolerans JCM1171 (T). The sequence of L. paracasei subsp. tolerans JCM1171 (T) was submitted to the NCBI. The ability to produce B-group vitamins was evaluated by high performance liquid chromatography. Lactobacillus strains and amount of vitamin B3, B6 and B9 production were analyzed by Analysis of Variance test. Results and Conclusion: Eleven isolates of Lactobacillus species from traditional yogurt samples were identified. Optimal conditions for Lactobacillus growth were pH 5-6 and temperatures 37-40°C. The isolates produced vitamins B3, B6 and B9. L. paracasei subsp. tolerance JCM 1171 (T) showed the highest amount of produced vitamins (p≤0.01) consist of vitamin B6 (1566.17 µg ml -1 ) and B9 (1279.72 µg ml -1 ). L. acidophilus strain KU showed the highest production of vitamin B3 (522.7 µg ml -1 ). L. fermentum produced the highest amount of vitamin B2. These strains are a natural and cost efficient source of vitamin. The Lactobacillus strains isolated in this research particularly, L. paracasei , could be applied in improving new fermented products, fortified with B-group vitamin that could be applied as substitution for enriching and supplementation with the controversial synthetic vitamins. Conflict of interest: The authors declare that there is no conflict of interest.