Abstract. Fe-Cr alloy is commonly being used as boiler tube's material. It is subjected to prolonged exposure to water vapor oxidation. The ability to withstand high temperature corrosion can normally be attributed to the formation of a dense and slow growing Cr-richoxide scale known as chromia, Cr 2 O 3 scale. However, oxidation may limit the alloy's service lifetime due to decreasing of its protectiveness capability. This paper is to presents an experimental study of thermo gravimetric and Fourier transform infrared analysis of Cr 2 O 3 at 1073 K in dry and humid environment. Samples were used from commercially available Cr 2 O 3 powder. It was cold-pressed into pellet shape of 12 mm diameter and 3 mm thick with hydraulic press for 40 min at 48 MPa. It then sintered at 1173 K in inert gas environment for 8 h. The samples are cooled and placed in 5 mm diameter platinum pan. It is subjected to reaction in dry and wet environment at 1073 K by applying 100%-Ar and Ar-5%H 2 gas. Each reaction period is 48 h utilizing Thermo Gravimetric Analyzer, TGA to quantify the mass changes. After the reaction, the samples then characterized with Fourier Transform Infrared Spectroscopy, FT-IR and Field Emission Electron Scanning Microscopy, FE-SEM. The TGA result shows mass decreasing ratio of Cr 2 O 3 in wet (P H 2 O =9.5x10 5 Pa) and dry environment is at a factor of 1.2 while parabolic rate at 1.4. FT-IR results confirmed that water vapor significantly broaden the peaks, thus promotes the volatilization of Cr 2 O 3 in wet sample. FESEM shows mostly packed and intact in dry while in wet sample, slightly porous particle arrangement compare to dry. It is concluded that water vapor species decreased Cr 2 O 3 protectiveness capability.

The concept of volunteering is more than just spending one's time in activities that bring benefit to others. Volunteering has a greater impact on society at a larger scale. University's students who actively involved in volunteering activities are of great help to the community as they will have a better chance in learning new opportunities and building new networking people from the industry. This paper aims to investigate the motivational strategies namely intrinsic and extrinsic motivation on volunteering intention among university students. The concept of religiosity is introduced as part of the motivational strategies as it is proven to be one of the students' motivational factor to volunteer.

There has been extensive discussion on the need to use corrective feedback in writing within foreign language learning. Essentially, corrective feedback is one of the important tools in improving students’ skills in learning a language. This study aims to find out the preference and justification of written corrective feedback (WCF) through the use of Google Docs among instructors and students in a higher learning institute. The effects of the direct and indirect feedback with metalinguistic comments were also studied to determine their suitability in teaching and learning the Arabic language. Quantitative and qualitative data were collected to (1) identify the preferred type of feedback among instructors and students, (2) identify justification of the preferred feedback type, and (3) examine post-test score differences between types of written correction feedback. Two questionnaires were adapted and distributed to 93 first-year students and four instructors of Arabic language for Academic Writing. Two instructors and five students were interviewed to find out their justification of the preferred types of WCF. A total of 50 respondents were divided into two groups according to the type of WCF provided, and post-test scores between the types of feedback were compared to determine if there was any significant difference between the types of feedback. The findings show that instructors prefer indirect WCF with metalinguistic comments while students prefer direct corrective feedback with metalinguistic comments.  Post-test scores indicate that higher scores were achieved by students who received indirect feedback with metalinguistic comments. This indicates that students are able to process indirect feedback that is supplemented with metalinguistic comments. Moreover, an online learning environment provides more opportunities for instructors to highlight the students’ errors more clearly.