RATERS’ FATIGUE AND THEIR COMMENTS DURING SCORING WRITING ESSAYS: A CASE OF IRANIAN EFL LEARNERS

Rating accuracy in writing among EFL learners is crucial in determining their English proficiency. Despite the importance of its accuracy, little is known about various factors may affect the accuracy of rating writing essays. This study examines how raters’ comments on EFL writing tasks change as a result of fatigue. To this end, four raters were selected and each given 28 essays to score and comment on. Six general types of raters’ comments (i.e., those on grammar, choice of words, organization, punctuation, dictation, and capitalization) were into focus in this study. Overall, results suggested that fatigue affects raters’ frequency of comments on grammar, choice of words, and organization, and that raters’ comments on punctuation, dictation, and capitalization do not seem to change significantly due to the effect of fatigue. Furthermore, this study revealed that the most and least frequent comments in 112 scored essays were those on grammar and dictation, respectively

General Extenders in Persian Discourse: Frequency and Grammatical Distribution

This study tries to investigate the frequency and grammatical distribution of general extenders in Persian. The analysis is based on a corpus of informal conversations. On some occasions, a comparison will also be made with the corpus of informal English compiled and analyzed by Overstreet (1999, 2005). The results of this study lay bare the fact that Persian speakers use adjunctive general extenders more frequently than disjunctive ones. It will also be demonstrated that Persian speakers use general extenders both at clause final and clause-internal positions. Finally, Persian general extenders will be examined with reference to their grammatical agreement requirements.Keywords: Discourse marker; frequency; general extender; grammatical distribution; Persia

Enhanced hydrogen storage performance of zinc and magnesium cobaltite nanocomposites

Renewable and sustainable energies are vital for the near future. Hydrogen, as a clean energy carrier, is a potential candidate for supplying energy in the foreseeable future. Nowadays, hydrogen storage technology has become a significant issue in the energy sector. In this study, ZnCo2O4/ZnO and MgCo2O4/MgO nanocomposites have been synthesized using the sol-gel method with stearic acid as a complexing agent. Different analyses were studied to examine the crystal structure, morphology, and physical properties of the as-prepared samples, including X-ray diffraction (XRD), Fourier transforms infrared (FT-IR), field emission scanning electron microscopy (FESEM), diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM). Various methods have been utilized for hydrogen storage technology. In a pioneering approach, the electrochemical hydrogen storage of samples was compared by the chronopotentiometry technique in KOH (4 M) electrolyte solution. The results reveal that ZnCo2O4/ZnO and MgCo2O4/MgO nanocomposites exhibit excellent discharge capacities of 4240 and 3529 mAh/g, respectively, after 11 cycles

DNA groove binding of an asymmetric cationic porphyrin and its Cu(II) complex: Resolved by spectroscopic, viscometric and molecular docking studies

In the present study, the interaction between water-soluble cationic asymmetric porphyrin, 5-(1-Hexadecyl pyridinium-4-yl)-10, 15, 20-tris (1-Butyl pyridinium-4-yl) Porphyrin Chloride, and its copper (II) derivative with calf thymus DNA (CT-DNA) were studied by means of spectroscopic techniques, viscosity measurements and molecular docking. The monitoring of the changes in visible absorbance spectra showed a small red shift and a little hypochromicity in the Soret band. Also, insignificant changes were appeared in the viscosity of DNA with increasing of the porphyrins. These results suggested that these porphyrins bound to DNA through the groove binding mode. Then, multivariate curve resolution-alternating least squares (MCR-ALS) method was employed on UV–visible spectral data matrix to resolve the spectral and concentration profiles of the components involved in the interaction and the binding constant was estimated by the combination of bard equation and MCR-ALS approach. Furthermore, molecular docking studies confirmed experimental results obtained by spectral techniques and provide deeper insight into the porphyrin-DNA interaction

Hydrothermal synthesis of graphene oxide/NiO and its influence on the thermal decomposition of ammonium perchlorate

278-284Graphene oxide/nickel oxide (GO/NiO) nanocomposite has been successfully synthesized through a one-step hydrothermal procedure. The GO/NiO nanocomposite is characterized by Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analysis. The influence of GO/NiO nanocomposites on the thermal decomposition of ammonium perchlorate (AP) is investigated by thermogravimetry, and differential scanning calorimetry analysis. The results reveal two stages thermal decomposition of pure AP changed to a one-stage highly exothermic process at much lower temperatures in the presence of GO/NiO nanocomposites. The released heat of AP thermal decomposition is increased from 649 J g-1 for pure AP (AP0) to 1259 and 2195 J.g-1, for AP:GO/NiO 97:3 (AP3) and 95:5 (AP5) mixtures, respectively. Furthermore, decomposition temperature of AP significantly has decreased from 419 °C (AP0) to 307 °C (AP3) and 287 °C (AP5). The kinetic parameters are calculated by Kissinger equation for thermal decomposition of AP0 and AP5. The catalytic activity of GO/NiO nanocomposite is revealed by pre-exponential factor and the calculated activation energy, also the decomposition rate constant is increased from 4.2 × 10-3 s-1 at 419 °C (pure AP) to 1.04 × 10-2 s-1 at 287 °C (peak temperature of AP5 sample)

Comparison of Coupled and Uncoupled Consolidation Equations Using Finite Element Method in Plane-Strain Condition

In the current paper, the consolidation settlement of a strip footing over a finite layer of saturated soil has been studied using the finite element method. In Biot’s coupled consolidation equations, the soil deformation and excess pore pressure are determined simultaneously in every time step which refers to the hydro-mechanical coupling. By considering a constant total stress throughout the time and by assuming that volume strain is a function of isotropic effective stress, uncoupled consolidation equations can be obtained using coupled consolidation equations. In these uncoupled equations, excess pore pressure and deformation are determined separately. In this approach, the excess pore pressure can be identified in the first stage. Using the calculated excess pore pressure, the soil deformation is determined through effective stress-strain analyses. A computer code was developed based on coupled and uncoupled equations that are capable of performing consolidation analyses. To verify the accuracy of these analyses, the obtained results have been compared with the precise solution of Terzaghi’s one-dimensional consolidation theory. The capability of these two approaches in estimation of pore water pressure and settlement and to show Mandel-Crayer’s effect in soil consolidation is discussed. Then, the necessity of utilizing coupled analyses for evaluating soil consolidation analysis was investigated by comparing the coupled and uncoupled analyses results

A new immunomodulatory drug delivery system based on αlβ2 and αmβ2 aptamers/Alg-PEI

Introduction: Currently, the major concern with biomaterial implantation or tissue grafting is adverse responses of immune system. To remove these barriers, some immunosuppressive drugs are used. But they are associated with adverse effects of systemical delivery. Adhesion of immune cells to foreign body by cell adhesion molecules such as integrins,triggers their activation that leads to immune response. It is demonstrated that this is directed by the ability of dendritic cells (DCs) to drive adaptive immune cells in situ toward adverse reactions and play as a bridge between innate and adaptive immune cells. Thus our focus is on β2 integrin receptors on DC. This study aims to modulate the immune response by inhibiting  β2integrins marker on DC. Methods and Results:to control of DC maturation,αlβ2 and αmβ2 surface markers on DCs should be blocked, hence, the novel aptamer-blocking technique was utilized. For this purpose, immature DCs (iDC) were derived from human peripheral blood monocytes. The antagonist biomolecules (aptamer) that simulated based on inverse of DC markers (αlβ2 and αmβ2) from selex,were embedded into injectable alginate-branched polyethyleneimine by physical entrapment. Then, derived iDCs were treated with synthesized hydrogels in RPMI-1640 media. Interaction of released antagonist aptamers from hydrogels andiDC was analyzed. DC adhesion and subsequently its maturation and potential for adaptive immune cell activation were measured by flowcytometry.When iDCs were treated with hydrogels the levels of DC markers (CD80 and CD86) expression as DC maturation criteria were measured. Expression level ratio for CD80 and CD86 to control sample show significant reduction, about 40 and 50, respectively. Released cytokinesfrom administrated DC by trappedaptamerswithAlg-PEI hydrogel indicate that DC behavior against a chemical foreign body was modulated considering the amount of released cytokines were decreased by10%. Conclusions:The results of this study demonstrated that this presented drug delivery system based on αlβ2 and αmβ2 aptamers can be used as an immune response modulator in health-related application. αlβ2 and αmβ2 aptamers as a new age of state of the art drug technology could be a good substitute for monoclonal antibody drugs to reduce their side effects and draw backs

Sol-gel synthesis, characterization, and electrochemical evaluation of magnesium aluminate spinel nanoparticles for high-capacity hydrogen storage

In this research, we successfully synthesized magnesium aluminate (MgAl2O4) spinel nanoparticles using a sol-gel process, with stearic acid serving as a capping agent. The synthesis process involved calcination at 900 °C for 4 h, resulting in the formation of nanoparticles with an average crystallite size of approximately 12 nm, as determined through Debye–Scherrer analysis and X-ray diffraction (XRD) data. The optical band gap was measured as 2.84 eV using Diffuse Reflectance Spectroscopy (DRS) analysis. Additionally, we found the mean pore size of the nanoparticles to be 20.2 nm through Brunauer–Emmett–Teller (BET) analysis. We characterized the resulting powders using various techniques, including Fourier Transform Infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-ray Spectroscopy (EDS), and Vibrating Sample Magnetometry (VSM). We conducted electrochemical investigations utilizing the Chronopotentiometry (CP) technique. The electrochemical analysis demonstrated that MgAl2O4 spinel nanoparticles exhibit a noteworthy hydrogen storage capacity of 4000 mAh/g, highlighting their potential as promising candidates for hydrogen storage applications. This comprehensive study underscores the successful synthesis, thorough characterization, and exceptional electrochemical performance of MgAl2O4 spinel nanoparticles, firmly positioning them as valuable materials for advancing hydrogen storage technologies