Iranian EFL Learners’ Attitudes toward Learning English through Computer and Technology in EFL Classes

The students learning English as a foreign language sometimes enjoy computer systems in their classes to do some class activities and tasks. The learners’ attitudes toward enjoying computer systems can help the teachers to be aware that computers in EFL classrooms are necessary. The aim of the present study is to investigate the EFL learners’ attitude toward learning English through computer systems in EFL classes. A hundred learners who learn English in Iranian EFL classes participated in this study. A questionnaire was adopted from a study done by Abdul Razak and Eswaran (2010). The data gathered in this study were analyzed through the related statistics and software and it is presented in percentage. The results showed that most of the learners who participated in this study had a positive attitude toward computer systems in EFL classes to learn English. It can also be said that using computer in EFL classes have beneficial and useful effects in learning by EFL learners and their learning can be improved via computers.Keywords: computer systems, EFL learner, attitud

Teachers’ Code Switching in an EFL Context: Why and When?

English is considered in Iran as a foreign language because Iranians enjoy this language in academic centers like schools and universities; therefore, the reasons of enjoying code switching in EFL classes can be considered as a study. This study was an attempt to investigate Iranian EFL teachers’ reasons for code switching in Iranian EFL classes by sixty Iranian teachers who teach English as a foreign language. This article, although preliminary in nature, attempted to highlight and explain some of the functions of code-switching in the foreign language classroom. In short, this study has been made to investigate the trends of code-switching in Iranian EFL classrooms. A questionnaire was adopted from Gulzar (2010) to know the reasons and functions toward code switching in EFL classes. Nine most important functions toward code switching were asked of the teachers to state their functions based on the Likert scale. The results showed that teachers have different reasons and functions for code switching in EFL classes. The reasons why code switching is used dependson different reasons such as time, syllabus, and subject matter and so on

Investigating Iranian EFL learners’ attitudes toward teachers’ code switching

Code switching is defined as change in language teaching to help learners understand the EFL points. Code switching can be enjoyed at different times in the EFL classes by the teachers and may be as a safe help to understand and comprehend the points and materials. The present paper is to analyze and study the Iranian learners’ attitudes toward teachers’ code switching in EFL classrooms. The researchers enjoyed a questionnaire adopted from a study done by Yao (2011). The questionnaire had 20 items in different topics. The learners’ attitudes toward the questionnaire’s items were stated in percentage form. The findings showed that most of the learners had a positive look toward code switching by their teachers because some EFL points are really difficult to understand and it is better to change the language of teaching and help learners achieve the EFL points

Correlation of Microstructure, Rheological and Morphological Characteristics of Synthesized Polypropylene (PP) Reactor Blends Using Homogeneous Binary Metallocene Catalyst

A novel binary homogeneous catalyst system based on (I): rac-Me2Si(2-Me-4-PhIn)2ZrCl2 and (II): (2-PhIn)2ZrCl2 catalysts at various molar ratios was utilized for the synthesis of polypropylene (PP) reactor blends with bimodal molecular weight distribution (MWD). The results of gel permeation chromatography analyses revealed that the catalyst (I) was responsible for the production of i-PP with high molecular weight (MW) while the individual use of catalyst (II) led to the production of an elastomeric PP with relatively low MW. However, application of the binary catalyst system led to high MW bimodal MWD products being highly dependent on the catalysts’ molar ratios. Increasing the molar ratio of catalyst (II) to catalyst (I) resulted in a notable enhancement of the products’ complex viscosity due to the increased MW, a higher level of chains’ entanglements and formation of amorphous blocks along the polymer chains. All products exhibited a single relaxation that shifted towards longer times upon changing the catalysts’ molar ratios. Scanning electron microscopy results revealed that the fracture surface of the blends, synthesized by the binary catalyst system, became more heterogeneous in comparison with the products obtained by the individual use of the catalyst (I). The observed heterogeneity was found to increase by increasing the amount of catalyst (II). Such morphological change was further corroborated by the dynamic rheological data, indicating a promising correlation between the linear rheological results and the morphological features of the synthesized PP reactor blends

Cure kinetics of epoxy nanocomposites affected by MWCNTs functionalization: A review

The current paper provides an overview to emphasize the role of functionalization of multiwalled carbon nanotubes (MWCNTs) in manipulating cure kinetics of epoxy nanocomposites, which itself determines ultimate properties of the resulting compound. In this regard, the most commonly used functionalization schemes, that is, carboxylation and amidation, are thoroughly surveyed to highlight the role of functionalized nanotubes in controlling the rate of autocatalytic and vitrification kinetics. The current literature elucidates that the mechanism of curing in epoxy/MWCNTs nanocomposites remains almost unaffected by the functionalization of carbon nanotubes. On the other hand, early stage facilitation of autocatalytic reactions in the presence of MWCNTs bearing amine groups has been addressed by several researchers. When carboxylated nanotubes were used to modify MWCNTs, the rate of such reactions diminished as a consequence of heterogeneous dispersion within the epoxy matrix. At later stages of curing, however, the prolonged vitrification was seen to be dominant. Thus, the type of functional groups covalently located on the surface of MWCNTs directly affects the degree of polymer-nanotube interaction followed by enhancement of curing reaction. Our survey demonstrated that most widespread efforts ever made to represent multifarious surface-treated MWCNTs have not been directed towards preparation of epoxy nanocomposites, but they could result in property synergism

INVESTIGATING THE RELATIONSHIP BETWEEN INCOME VARIATION AND EFFICIENCY OF BANKS ACCEPTED IN THE STOCK EXCHANGE

Abstract. The purpose of this research was to investigate the relationship between income variation and efficiency of banks accepted in the stock exchange. This research is descriptive-correlative method and is of applied research type. The statistical population of the study is all banks accepted in the Tehran Stock Exchange during the years 2012 to 2016, in which 15 banks have been active throughout the entire period of the research in the stock market. The research data were extracted from financial statements of banks and analyzed using regression models using combination data. The research findings showed that there was a relationship between the size of the bank and the efficiency of the banks accepted in the stock exchange, as well as between the equity and the efficiency of the banks accepted to the stock exchange.Keywords: Income Variation, Bank Efficiency, Bank Size, Equity

Evaluation of Matrix Metalloproteinase 2 and 9 Activity in Patients with Prostate Cancer and Benign Prostate Hyperplasia Compared with Healthy Individuals

Background and Aim: Prostate cancer (PC) is one of the most prevalent cancers with high mortality and morbidity in men, which can be treated in different ways before the progression and metastasis to distant organs. Destruction of extracellular matrix by matrix metalloproteinase (MMP), particularly by the 2 and 9 subtypes, has an important role in the metastasis of PC. We aimed to assess the activity of MMP 2 and 9 and some related metalloproteinases in PC and with benign prostate hyperplasia (BPH) patients in comparison to healthy individuals. Methods: In this case-control study, 72 individuals referred to Imam Khomeini hospital (Tehran, Iran), have been divided into 3 groups, including PC, BPH, and healthy control. Age and body mass index (BMI) for all groups have been matched. Venous blood samples were used to assess the enzyme activity by the zymography technique. Results: The activity of MMP-2 and 9 was significantly higher in PC than BPH and control groups. But there was no difference in the activity of enzymes in patients with PC according to the Gleason score. Conclusion: The results suggested that MMPs activity can be considered a diagnostic marker for PC. However, further studies are required to establish this concept. *Corresponding Author: Abbas Khonakdar-Tarsi; Email: [email protected] Please cite this article as: Shojaee M, Mohammadi P, Jafarpour H, Pouriamehr S, Barmaki H, Khonakdar-Tarsi A. Evaluation of Matrix Metalloproteinase 2 and 9 Activity in Patients with Prostate Cancer and Benign Prostate Hyperplasia Compared with Healthy Individuals. Arch Med Lab Sci. 2020;6:1-6(e12). https://doi.org/10.22037/amls.v6.3237

Cure Kinetics of Epoxy Nanocomposites Affected by MWCNTs Functionalization: A Review

The current paper provides an overview to emphasize the role of functionalization of multiwalled carbon nanotubes (MWCNTs) in manipulating cure kinetics of epoxy nanocomposites, which itself determines ultimate properties of the resulting compound. In this regard, the most commonly used functionalization schemes, that is, carboxylation and amidation, are thoroughly surveyed to highlight the role of functionalized nanotubes in controlling the rate of autocatalytic and vitrification kinetics. The current literature elucidates that the mechanism of curing in epoxy/MWCNTs nanocomposites remains almost unaffected by the functionalization of carbon nanotubes. On the other hand, early stage facilitation of autocatalytic reactions in the presence of MWCNTs bearing amine groups has been addressed by several researchers. When carboxylated nanotubes were used to modify MWCNTs, the rate of such reactions diminished as a consequence of heterogeneous dispersion within the epoxy matrix. At later stages of curing, however, the prolonged vitrification was seen to be dominant. Thus, the type of functional groups covalently located on the surface of MWCNTs directly affects the degree of polymer-nanotube interaction followed by enhancement of curing reaction. Our survey demonstrated that most widespread efforts ever made to represent multifarious surface-treated MWCNTs have not been directed towards preparation of epoxy nanocomposites, but they could result in property synergism

Surface modification of MWCNT and its influence on properties of paraffin/MWCNT nanocomposites as phase change material

Multiwalled carbon nanotubes (MWCNTs) were modified by an organo-silane in order to improve their dispersion state and stability in paraffin wax. A family of paraffin-based phase change material (PCM) composites filled with MWCNTs was prepared with different loadings (0, 0.1, 0.5, and 1 wt%) of pristine MWCNTs and organo-silane modified MWCNTs (Si-MWCNT). Structural analyses were performed by means of Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and rheological studies using temperature sweeps. Moreover, phase change transition temperatures and heat of fusion as well as thermal and electrical conductivities of the developed PCM nanocomposites were determined. The SEM micrographs and FTIR absorption bands appearing at approximately 1038 and 1112 cm−1 confirmed the silane modification. Differential scanning calorimetery (DSC) results indicate that the presence of Si-MWCNTs leads to slightly favorable enhancement in the energy storage capacity at the maximum loading. It was also shown that the thermal conductivity of the PCM nanocomposites, in both solid and liquid phases, increased with increasing the MWCNT content independent of the kind of MWCNTs by up to about 30% at the maximum loading of MWCNTs. In addition, the modification of MWCNTs made the samples completely electrically nonconductive, and the electrical surface resistivity of the PCMs containing pristine MWCNTs decreased with increasing MWCNTs loading. Furthermore, the rheological assessment under consecutive cyclic phase change demonstrated that the samples containing modified MWCNTs are more stable compared to the PCM containing pristine MWCNTs. © 2019 Wile