EFL Learners` Self-Perceived Strategy Use across Various Intelligence Types: A Case Study

( Abdorreza Tahriri ),( Hoda Divsar ) 범태평양응용언어학회 2011 범태평양응용언어학회지 Vol.15 No.1

Increasing attention paid to learner-centered pedagogy in recent years has highlighted the examination of intelligence and language learning strategies (LLSs) among others. This study explores EFL learners` perceived use of language learning strategies across various intelligence types as reflected in Gardner`s 1983 Multiple Intelligences Theory. Ninety BA Junior English majors studying at Islamic Azad University of Rasht participated in the present study. Two self-reported inventories, Multiple Intelligences Survey (Armstrong, 1993) and Strategy Inventory for Language Learning (SILL) (ESL/EFL Version) developed by Oxford (1990), were utilized to determine the participants` intelligence profile and their perceived strategy use. The findings of the study revealed that intelligence did not significantly affect the overall strategy use of the participants. All types of intelligence fell within the ``medium`` user of LLSs. However, participants of verbal linguistic type were found to be higher in terms of their strategy use and visual-spatial students were the lowest strategy users overall. In addition, participants of verbal-linguistic type were found to be higher users of cognitive strategies. In terms of metacognitive strategies, verballinguistic, bodily-kinesthetic, interpersonal, intrapersonal and naturalist were found to be higher than logical-mathematical, visual-spatial and musical-rhythmic types. Visual-spatial learners were also found to be lower in terms of their use of social strategies. The conclusions of the study along with related pedagogical implications are explained.

Effect of manganese (Mn) doping on the optical properties of zinc sulfide (ZnS) semiconductor nanocrystals

Mohammadreza Tahriri,Elham Mohagheghpour,Mohammad Rabiee,Fathollah Moztarzadeh 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.2

In this research, we report the synthesis of ZnS nanocrystals with a size range of 1-10 nm in diameter with varying manganese (Mn) concentrations. Various samples of Zn1-x MnxS, with x = 0.0001, 0.007, 0.02, 0.03, 0.055, 0.09 and 0.13, have been prepared from a quaternary W/O microemulsion system. It is observed that by adding Mn to ZnS nanoparticles, the emission intensity changed and by using 5.5% magnesium for total Zn+2, a maximum emission were achieved. A photoluminescence (PL) study was carried out by band-to-band excitation (λex = 293 nm and 321 nm) upon ZnS : Mn, which results in two emission peaks corresponding to surface states and Mn+2 emission. Also, we observe orange emission from Mn2+ ions in the doped ZnS nanocrystals, apart from the blue emission characteristic of the ZnS defect states. The relative intensity of the orange emission compared with the blue varies with the manganese concentration in a nonmonotonic way. For analyses of the quality and quantity of this product, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), inductive coupled plasma (ICP), and spectrograph techniques were used.

A UG-Based Account of the Second Language Acquisition of English Restrictive Relative Clauses: An Overview

( Abdorreza Tahriri ),( Firooz Sadinghi ) 범태평양응용언어학회 2006 범태평양응용언어학회지 Vol.10 No.2

Nanostructured Hydroxyapatite for Biomedical Applications: From Powder to Bioceramic

Eslami, Hossein,Tahriri, Mohammadreza,Moztarzadeh, Fathollah,Bader, Rizwan,Tayebi, Lobat The Korean Ceramic Society 2018 한국세라믹학회지 Vol.55 No.6

In this study, a wet chemical method was used to synthesize nanostructured hydroxyapatite for biomedical applications. Diammonium hydrogen phosphate and calcium nitrate 4-hydrate were used as starting materials with a sodium hydroxide solution as an agent for pH adjustment. Scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, differential thermal analysis, thermal gravimetric analysis, atomic absorption spectroscopy, and ethylenediaminetetraacetic acid (EDTA) titration analysis were used to characterize the synthesized powders. Having been uniaxially pressed, the powders formed a disk-like shape. The sinterability and electrical properties of the samples were examined, and the three-point bending test allowed for the measurement of their mechanical properties. Sedimentation analysis was used to analyze the slurry ability of hydroxyapatite. As in-vitro biological properties of the samples, biocompatibility and cytotoxicity were assessed using osteoblast-like cells and the L929 cell line, respectively. Solubility was assessed by employing a simulated body fluid.

Investigating the Effectiveness of an Integrated Approach to Teaching Literature in an EFL Context

( Hoda Divsar ),( Abdorreza Tahriri ) 범태평양응용언어학회 2009 범태평양응용언어학회지 Vol.13 No.2

In the present paper, three models for teaching literature including language-based, literature as content or culture, and literature as personal growth or enrichment were evaluated. Based on these models, an integrated model was suggested. An experimental study was carried out in order to examine the effectiveness of the suggested approach compared to a conventional and instructor-led one. One-hundred and twenty BA students majoring in English Literature took part in a one-semester experiment. For the experimental group, the integrated approach was utilized whereas the method used for the control group was based on content-cultural model according to which the course instructor provided all the necessary information without focusing on the linguistic or stylistic considerations. The post-test consisted of three parts: linguistic, interpretive and cultural sections. The results of the study confirmed the plausibility of the use of the suggested eclectic approach to teaching literature. Several pedagogical implications were drawn.

A Survey of EFL Instructors` Mediative Knowledge across Contexts of Teaching

Najafquli Rezaee-Manesh,Abdorreza Tahriri 범태평양 응용언어학회 2014 범태평양응용언어학회지 Vol.18 No.2

The current mixed-method study probed EFL instructors`` mediative knowledge across four different contexts of teaching including language institutes, universities, and senior and junior high schools in Iran. To this end, 181 EFL instructors, 80 males and 101 females, completed mediative closed-questionnaire which composed of twelve items to measure EFL instructors`` knowledge of mediation across context. Out of 181, 72 participants, 16 (22%) institute instructors, 20 (28%) university instructors, 19 (26.38%) senior instructors, and 17 (23.61%) junior instructors participated in oral interview. Results of descriptive statistics and Chi-square showed that there exist significant differences among EFL instructors in seven mediative items; furthermore, the difference shows that there exists relationship between EFL instructors`` mediative knowledge across the contexts; however, in five mediative items, no differences were found across contexts. Results of oral interview of EFL instructors in terms of assessment revealed that they mostly believed that learners through instructors`` guidance should self-assess their learning and behavior. To achieve such an end, they suggested instructors`` step by step scaffolding and strategic deliverance of assessment to the learners. In terms of cooperation and individualization, the results of oral interview revealed that instructors believed in unified improvement of both of them. To improve both, pair and group works were suggested to boost cooperation whereas competition and individual activities were suggested to foster individualization. Context variation due to its own community and unique characteristics, learners`` potential to self-assess their learning, and development of whole learner were suggested to be taken into consideration by instructors, educationalists, parents, and curriculum, and course designers.

A Survey of EFL Instructors` Mediative Knowledge across Contexts of Teaching

( Rezaee Manesh,N. ),( Tahriri A. ) 범태평양응용언어학회 2014 범태평양응용언어학회지 Vol.18 No.2

The current mixed-method study probed EFL instructors`` mediative knowledge across four different contexts of teaching including language institutes, universities, and senior and junior high schools in Iran. To this end, 181 EFL instructors, 80 males and 101 females, completed mediative closed-questionnaire which composed of twelve items to measure EFL instructors`` knowledge of mediation across context. Out of 181, 72 participants, 16 (22%) institute instructors, 20 (28%) university instructors, 19 (26.38%) senior instructors, and 17 (23.61%) junior instructors participated in oral interview. Results of descriptive statistics and Chi-square showed that there exist significant differences among EFL instructors in seven mediative items; furthermore, the difference shows that there exists relationship between EFL instructors`` mediative knowledge across the contexts; however, in five mediative items, no differences were found across contexts. Results of oral interview of EFL instructors in terms of assessment revealed that they mostly believed that learners through instructors`` guidance should self-assess their learning and behavior. To achieve such an end, they suggested instructors`` step by step scaffolding and strategic deliverance of assessment to the learners. In terms of cooperation and individualization, the results of oral interview revealed that instructors believed in unified improvement of both of them. To improve both, pair and group works were suggested to boost cooperation whereas competition and individual activities were suggested to foster individualization. Context variation due to its own community and unique characteristics, learners`` potential to self-assess their learning, and development of whole learner were suggested to be taken into consideration by instructors, educationalists, parents, and curriculum, and course designers.

Formation of hydroxyapatite nanoneedles on the surface of a novel calcium phosphate/blood plasma proteins biocement in simulated body fluid (SBF)

Mahdi Rezvannia,Fathollah Moztarzadeh,Mohammadreza Tahriri 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.5

In this study, we report on needle-like hydroxyapatite grown on the surface of calcium phosphate/blood plasma proteins biocement in simulated body fluid (SBF). Scanning electron microscope revealed the formation of nano-sized needle-like hydroxyapatite crystals on the surface of the biocement after 7 days immersion in the simulated body fluid. X-ray diffraction analysis of the biocement structures indicated that the nanoneedle crystals were hydroxyapatite. Finally Fourier transform infra-red investigations were employed to detect the functional groups of the biocement which this technique demonstrated to be hydroxyapatite. In this study, we report on needle-like hydroxyapatite grown on the surface of calcium phosphate/blood plasma proteins biocement in simulated body fluid (SBF). Scanning electron microscope revealed the formation of nano-sized needle-like hydroxyapatite crystals on the surface of the biocement after 7 days immersion in the simulated body fluid. X-ray diffraction analysis of the biocement structures indicated that the nanoneedle crystals were hydroxyapatite. Finally Fourier transform infra-red investigations were employed to detect the functional groups of the biocement which this technique demonstrated to be hydroxyapatite.

Synthesis and characterization of nanocrystalline fluorinated hydroxyapatite powder by a modified wet-chemical process

Hossein Eslami,Mehran Solati-Hashjin,Mohammadreza Tahriri 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.3

Fluorinated hydroxyapatite (FHA; fluorhydroxyapatite) powder was synthesized through a pH-cycling method by varying the sodium fluoride [NaF] concentration in a hydroxyapatite suspension as a modified wet-chemical process. The powder sample was characterized by the commonly used bulk techniques of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), F-selective electrode, atomic absorption spectroscopy (AAS) and EDTA titration analyses. SEM was used to estimate the particles size of the powder and observe the morphology and agglomeration state of the powder. The functional groups presented in the synthesized powder were ascertained by FTIR investigations. AAS and EDTA titration techniques were employed for calculation of the Ca/P molar ratio. F-selective electrode analysis also was used to measure the fluorine (F) content in the crystalline network of the synthesized powder. Finally, the FHA and other phases according to processing parameters were observed by XRD analysis Fluorinated hydroxyapatite (FHA; fluorhydroxyapatite) powder was synthesized through a pH-cycling method by varying the sodium fluoride [NaF] concentration in a hydroxyapatite suspension as a modified wet-chemical process. The powder sample was characterized by the commonly used bulk techniques of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), F-selective electrode, atomic absorption spectroscopy (AAS) and EDTA titration analyses. SEM was used to estimate the particles size of the powder and observe the morphology and agglomeration state of the powder. The functional groups presented in the synthesized powder were ascertained by FTIR investigations. AAS and EDTA titration techniques were employed for calculation of the Ca/P molar ratio. F-selective electrode analysis also was used to measure the fluorine (F) content in the crystalline network of the synthesized powder. Finally, the FHA and other phases according to processing parameters were observed by XRD analysis

The influence of some processing conditions on host crystal structure and phosphorescence properties of SrAl2O4:Eu2+, Dy3+ nanoparticle pigments synthesized by combustion technique

Ehsan Shafia,Masoud Bodaghi,Mohammadreza Tahriri 한국물리학회 2010 Current Applied Physics Vol.10 No.2

The spectroscopic and host phase properties of SrAl2O4:Eu2+, Dy3+ phosphors with a series of different initiating combustion temperature, urea concentration as a fuel and critical pH of precursor solution are investigated. The SrAl2O4:Eu2+, Dy3+ nanoparticle pigments were obtained by exothermic combustion process within less than 5 min. The sample that ignited at initiating combustion temperature of 600 ℃exhibits highest intensity emission peak at 517 nm in which the SrAl2O4 host phase has the maximum fraction of monoclinic SrAl2O4 phase. The excitation spectra consist of 240 and 254 nm broad peaks. The experimental results show that the optimum ratio of urea is 2.5 times higher than theoretical quantities for best emission condition of SrAl2O4:Eu2+, Dy3+ phosphor particles. The critical pH was obtained about 5.2. The crystallite size of these pigments is about 40 nm before thermal treatment and 62 nm after thermal treatment, respectively.