The effect of annealing to the hardness of high Y2O3-Oxide dispersion strengthened (ODS) ferritic steels

The purpose of this study was to investigate the effect of annealing to the hardness of high Y2O3-oxide dispersion strengthened (ODS) ferritic steels. The samples were prepared by mechanical alloying method followed by Cold Isostatic Pressing (CIP). After compaction process, the samples were sintered at 1100°C for 1 h in a tube furnace. The crystal structure and morphology of samples were analyzed by X-ray Diffraction (XRD) measurement and characterized by using field emission scanning electron microscope (FESEM), respectively. The hardness of samples was measured by using a micro-Vickers hardness tester with a load of 200 gf at annealing temperature of 600°C, 800°C and 1000°C, respectively. The Vickers hardness value (HV0,2) versus annealing temperature graph showed that the hardness of all samples started to decrease at temperature of 600°C due to grain growth. The hardness value of all samples (1Y and 5Y) identified at this annealing temperature is 855 HV0,2 and 808 HV0, 2, respectively

Magnetotransport properties of La0.67Ca0.33MnO3 with different grain sizes

The magnetotransport and magnetoresistive (MR)properties of manganese-based La0.67Ca0.33MnO3 perovskite with different grain sizes are reported. The electrical resistivity was measured as a function of temperature in magnetic fields of 0.5 and 1 T. The insulator–metal transition temperature, TIM, shifted to a higher temperature with the application of the magnetic field. In zero field, TIM is almost constant (∼271 K) for all samples except for the sample with the largest grain size, where TIM = 265 K. The temperature dependence of resistivity was fitted with several equations in the metallic (ferromagnetic) region and the insulating (paramagnetic) region. The density of states at the Fermi level, N(EF), and the activation energy of electron hopping were estimated by fitting the resistivity versus temperature curves. The ρ–T 2 curves are nearly linear in the metallic regime, but the ρ–T 2.5 curves exhibit a deviation from linearity. The variable range hopping model and small polaron hopping model fit the data well in the high-temperature region,indicating the existence of the Jahn–Teller distortion that localizes the charge carriers. MR was found to increase with an increase in the magnetic field, an effect which is attributed to the intergrain spin tunneling effect

The Effect of Passive Opium Smoking on Cardiovascular Indices of Rabbits with Normal and Ischemic Hearts

Some Asian people believe that opium can protect the cardiovascular system. To assess this belief, we investigated the effect of passive opium smoking (POS) on cardiovascular indices in rabbits with ischemic and non-ischemic hearts

Colours as a form of corrective feedback in EFL learners’ writing

The study aims to explore the effect of colours as a form of corrective feedback in EFL learners’ writing and how the foregrounding of such feedback is related to the learners’ performance in EFL acquisition. Data were collected from a group of EFL learners, in which majority of them came from the Middle East countries. A pre-test and a post-test were conducted to determine the types of grammatical errors that they committed the most. The result of the study revealed that colour corrective feedback was found to be effective in increasing learners’ awareness which had improved learners’ performance in writing. After receiving corrective feedback in the form of colours, it was found that grammatical errors, specifically mechanical and morphological errors committed by the learners had decreased tremendously whereas in terms of semantic errors, the number of errors had increased. This result supports the notion of Noticing Hypothesis whereby learning is effective when the errors are noticed. The use of colours in highlighting specific errors was also found to assist learners to progress further and faster in the learning process as the types of errors committed can immediately be identified. This study enlightens the usage of colour-coded system as a form of indirect corrective feedback for language instructors specifically in EFL context. Thus, the pedagogical implication of this study is that colours could be used as a form of indirect corrective feedback due to its ability to immediately direct students’ focus towards specific grammatical errors

Recent progress on supercapacitive performance of agrowaste fibers: a review

The waste-to-wealth practice has evolved into the circular economy concept, in which every by-product is converted into a usable product, enabling the concept of zero-waste. As a result, research on converting wastes, particularly bio and agricultural wastes, into usable products is prioritized. Activated carbons are one of these products, which are derived through a variety of physical and chemical processes from agricultural and biowaste. These activated carbons have applications in various fields, including energy storage, catalysis, and water purification. However, the quality of this activated carbon is dependent on the bioresource's structure and chemical composition. As a result, many sources to produce activated carbon, including stems, wood, leaves, root, bark, fiber, flower, and seeds, have been identified and are being explored for their potential use as an electrode material for supercapacitors. Out of these sources, fiber from different bioresources shows improved performance as supercapacitor electrodes due to their higher cellulose and lignin contents. In this study, we systematically review various sources of activated carbon and their performance as supercapacitor electrodes. The electrochemical characterization methodologies used to characterize this fiber-based activated carbon are examined critically, and factors influencing its improved/poor performance are collated. Additionally, the most performing fiber-based sources of activated carbon for supercapacitor electrodes are identified, along with a future perspective.</p