Reflective Thinking and Reflective Teaching among Iranian EFL Teachers: Do Gender and Teaching Experience Make a Difference?

AbstractThe present study investigated the relationship between reflective teaching and reflective thinking of Iranian EFL teachers regarding gender and teaching experience. To this end, 233 teachers were surveyed using English Language Teaching Reflection Inventory (Akbari, Behzadpoor, & Dadvand, 2010), and Teachers’ Reflective Thinking Questionnaire (Choy & Oo, 2012). The results of Pearson product moment correlation indicated there was a significant positive correlation between reflective teaching and reflective thinking of Iranian EFL teachers. The results of Independent Samples t-tests revealed significant differences between male and female Iranian EFL teachers in terms of both reflective teaching and reflective thinking. The results of one-way ANOVA and Tukey post-hoc analysis respectively indicated that teaching experience significantly differentiated Iranian EFL teachers concerning reflective teaching, i.e. high-experienced teachers significantly outperformed mid-experienced teachers who, in turn, outperformed their low-experienced counterparts in this regard

Static Eccentricity Fault Detection in Brushless Doubly Fed Induction Machines based on MotorCurrent Signature Analysis

In this paper a new rotor eccentricity fault detection method is proposed for the first time for Brushless Doubly Fed Induction Machines (BDFIMs). Due to the fact that BDFIMs are attractive alternatives to doubly fed induction machines for wind power generation, paying attention to their fault diagnosis is essential. Existing fault detection methods for conventional induction machines can not be directly applied to the BDFIM due to its special rotor structure and stator winding configurations as well as the complex magnetic fields. In this paper a new fault detection technique based on stator current harmonic analysis is proposed to detect rotor eccentricity faults in the BDFIM. The validity of the proposed fault detection method is verified by analytical winding function method and finite element analysis on a prototype D180 BDFIM. Index Terms—Brushless doubly fed induction machines, Nested-loop rotor slot harmonics, Motor current signature analysis, Winding function method, Finite element analysis, Static eccentricity fault

Eccentricity fault detection in brushless doubly fed induction machines

Abstract: A new fault diagnosis method for detecting the rotor eccentricity faults including static, dynamic and mixed eccentricity is proposed for brushless doubly‐fed induction machines (BDFIMs). BDFIMs are attractive alternatives for the conventional doubly‐fed induction generator (DFIG) for offshore wind power generation; therefore, paying attention to their fault detection is essential. Existing fault detection methods for conventional induction machines cannot be directly applied to the BDFIM due to its special rotor structure and stator winding configurations as well as complex magnetic field patterns. This article proposes a novel fault detection method based on motor current signal analysis to determine stator current harmonics, induced by the nested‐loop rotor slot harmonics (NRSHs), as fault indices. The analysis is performed under healthy conditions and with different types of rotor eccentricity. Finally, a sensitivity analysis is carried out to confirm the practicability of the proposed technique with various fault intensities and load conditions. Analytical winding function approach, finite element analysis and experimental tests on a prototype D180 BDFIM are used in this study to validate the proposed fault detection technique

A New Stator Winding Inter-Turn Short Circuit Fault Detection Method For Brushless Doubly Fed Induction Machine

The brushless Doubly Fed Induction Machine (BDFIM) with high reliability and robust structure demonstrates technical and commercial advantages both as a generator and motor for variable speed drive applications. As a generator it is particularly attractive to be used in offshore wind turbines where reliability improvement and maintenance cost reduction are the key factors in wind power market growth. As a motor it can be utilized in application requiring adjustable speed operation. Inter-turn short circuit fault is one of the most frequent electrical faults in electric machines, which can also be the cause of other stator winding faults in the machine, hence its early detection can significantly reduce the maintenance cost and improve reliability. In this paper a novel fault detection method for inter-turn short circuit fault is proposed for the BDFIM based on the discrete wavelet transform of the stator winding currents. The analytical winding function method as well as the finite element analysis of an experimental D180 BDFIM is used in order to verify the proposed fault detection method

The normoglycemic first-degree relatives of patients with type 2 diabetes mellitus have low circulating omentin-1 and adiponectin levels

Objective: It has been suggested that adipose-derived cytokines act as insulin sensitizers/insulin-mimetics and some others may induce insulin resistance. In order to elucidate the potential role of novel adipocytokines in the pre-diabetes states, circulating levels of novel adipocytokines were evaluated in first-degree relatives of subjects with type 2 diabetes mellitus (FDRs). Method: Serum omentin-1, adiponectin and retinol-binding protein 4 (RBP4) levels were measured in 179 subjects (90 glucose tolerant FDRs and 89 age- and sex-matched healthy controls) using enzymelinked immunosorbent assay (ELISA) methods. Results: There was no significant difference between the two groups regarding serum RBP4 concentrations. However, serum omentin-1 (median [interquartile range], 6.18 [4.06–11.52] ng/ml versus 10.50 [4.30– 20.60] ng/ml, p = 0.004) and adiponectin (mean ± SD, 10.07 ± 4.0 lg/ml versus 20.66 ± 8.12 lg/ml, p < 0.0001) levels were significantly lower in FDRs when compared with the controls. In multiple logistic regression analysis, FDRs showed a significant association with lower circulating omentin-1 and adiponectin levels, even after adjustments were made for age, sex, body mass index, blood pressure measures, and biochemical parameters including glucose status, lipid profile, insulin levels and HOMA-IR (OR = 0.49, CI [0.30–0.79]; p = 0.004 and OR = 0.74, CI [0.67–0.82]; p < 0.0001, respectively). However, FDRs did not show a significant association with serum RBP4 levels in different models of regression analyses. Conclusions: The FDRs showed significant associations with lower omentin-1 and adiponectin levels. A potential role for these adipokines in the FDRs’ increased risk of diabetes needs to be further elucidated

Correlation of Circulating Omentin-1 with Bone Mineral Density in Multiple Sclerosis: The Crosstalk between Bone and Adipose Tissue

BACKGROUND: Patients with multiple sclerosis (MS) are at increased risk of osteoporosis and fractures. Adipose tissue-derived adipokines may play important roles in the osteoimmunology of MS. In order to determine whether omentin-1 and vaspin may be related to bone health in MS patients, we compared circulating levels of these recently identified adipokines, between MS patients and healthy controls. METHODS: A total of 35 ambulatory MS patients with relapsing-remitting courses were compared with 38 age- and sex-matched healthy controls. Bone mineral density (BMD) was determined for the lumbar spine (L2-L4) and the proximal femur using dual-energy x-ray absorptiometry. Circulating omentin-1, vaspin, osteocalcin, osteopontin, osteoprotegerin, the receptor activator of nuclear factor-κB ligand, matrix metalloproteinase 9, C-reactive protein and 25-hydroxy vitamin D levels were evaluated by highly specific enzyme-linked immunosorbent assay methods. RESULTS: There was no significant difference between the two groups regarding bone-related cytokines, adipocytokines, and the BMD measurements of patients with MS and the healthy controls. However, in multiple regression analysis, serum omentin-1 levels were positively correlated with BMD at the femoral neck (β = 0.49, p = 0.016), total hip (β = 0.42, p = 0.035), osteopontin (β = 0.42, p = 0.030) and osteocalcin (β = 0.53, p = 0.004) in MS patients. No correlations were found between vaspin, biochemical, and BMD measures in both groups. CONCLUSIONS: Elevated omentin-1 serum levels are correlated with BMD at the femoral neck and the serum levels of osteocalcin and osteopontin in MS patients. Therefore, there is crosstalk between adipose tissue and bone in MS

Improvement of the entanglement generation in atomic states using a single-mode field in the Tavis–Cummings model

Assuming the interaction of two separable two-level atoms with a single-mode field in the Tavis–Cummings model, we investigate the entanglement generation in the atomic state using the concurrence measure. Specifically, even and odd coherent states are selected as the initial states of the field and the entanglement of the final atomic state is computed and compared with the corresponding one when the ordinary coherent state is the initial field state. It is observed that even and odd coherent states induce more entanglement in the atomic state, so that the Bell states can be obtained by optimizing the parameters. In addition, we observe a direct connection between the non-Gaussianity of field states and the entanglement of atomic states. Also, a mixture of separable and entangled states is generated with the passage of time and the range of entanglement variation decreases

System Dynamics Modeling of Phytoplankton and Zooplankton in Reservoirs

The need for predictive water quality modeling has arisen largely as a result of increased eutrophication of lakes throughout the world. In 1919 Nauman introduced the concept of oligotrophy and eutrophy, distinguishing oligotorophic lakes with little panktonic algae and eutrophic lakes containing much phytoplankton. The phytoplankton consist of the assemblage of small plants having no or very limited powers of locomotion. A variety of formulations have been developed to represent the effect of temperature, light, and nutrient on phytoplankton growth. A number of processes contribute to the loss rate of phytoplankton. These processes are: respiration, excretion and predatory losses. The zooplankton include animals suspended in water with limited power of locomotion. Phytoplankton as well as zooplankton are usually denser than water, and constantly sink by gravity to lower depths. System dynamics is a method of solving problems by computer simulation. The typical purpose of a system dynamics study is to understand how and why the dynamics of concern are generated and to search for managerial policies to improve the situation. In this paper phytoplankton and zooplankton are simulated by system dynamics approach. Then we integrated a limiting nutrient into our phytoplankton-zooplankton scheme to complete our fundamental picture of how nutrient/food-chain interactions are modeled