Browsing by Author "Mechanical and Energy Engineering, School of Engineering and Technology, IUPUC"

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    Corrosion resistance and thermal stability of sputtered Fe44Al34Ti7N15 and Al61Ti11N28 thin films for prospective application in oil and gas industry
    (Elsevier, 2021-10-01) Maruf, Mahbub Alam; Rizvi, Syed Muhammad Mujtaba; Noor-A-Alam, Mohammed; Shin, Donghyun; Haider, Waseem; Shabib, Ishraq; Mechanical and Energy Engineering, School of Engineering and Technology, IUPUC
    Fe-and Al-based thin-film metallic glass coatings (Fe44Al34Ti7N15 and Al61Ti11N28) were fabricated using magnetron co-sputtering technique, and their corrosion performances compared against wrought 316L stainless steel. The results of GI-XRD and XPS analyses demonstrated amorphous structure and oxide layer formation on the surface of the fabricated thin films, respectively. The potentiodynamic (PD) polarization test in chloride-thiosulfate (NH4Cl ​+ ​Na2S2O3) solution revealed lower corrosion current (Icorr) (0.42 ​± ​0.02 ​μA/cm2 and 0.086 ​± ​0.001 ​μA/cm2 Vs. 0.76 ​± ​0.05 ​μA/cm2), lower passivation current (Ipass) (1.45 ​± ​0.03 ​μA/cm2 and 1.83 ​± ​0.07 ​μA/cm2 Vs. 1.98 ​± ​0.04 ​μA/cm2), and approximately six-fold higher breakdown potential (Ebd) for Fe- and Al-based coatings than those of wrought 316L stainless steel. Electrochemical Impedance Spectroscopy (EIS) of both films showed 4- and 2-fold higher charge transfer resistance (Rct), 7- and 2.5-times higher film resistance (Rf), lower film capacitance values (Qf) (10 ​± ​2.4 ​μS-sacm-2, and 5.41 ​± ​0.8 ​μS-sacm-2 Vs. 18 ​± ​2.21 ​μS-sacm-2), and lower double-layer capacitance values (Qdl) (31.33 ​± ​4.74 ​μS-sacm-2, and 15.3 ​± ​0.48 ​μS-sacm-2 Vs. 43 ​± ​4.23 ​μS-sacm-2), indicating higher corrosion resistance of the thin films. Cyclic Voltammetry (CV) scan exhibited that the passive films formed on the Fe- and Al-based coatings were more stable and less prone to pitting corrosion than the wrought 316L stainless steel. The surface morphology of both films via SEM endorsed the CV scan results, showing better resistance to pitting corrosion. Furthermore, the thermal analysis via TGA and DSC revealed the excellent thermal stability of the thin films over a wide temperature range typically observed in oil-gas industries.
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    Development and Use of Open Educational Resources in an Undergraduate Heat and Mass Transfer Course
    (American Society of Engineering Education, 2021-07-26) Mendez, Julie; Mechanical and Energy Engineering, School of Engineering and Technology, IUPUC
    Higher education costs have been increasing more rapidly than inflation over the last few decades. One way to decrease textbook costs is to use open educational resources (OER), which are materials licensed in a way that allows everyone to engage in the “5R activities”: retain, reuse, revise, remix and redistribute. The most significant benefits of using OER or other no-cost digital materials instead of traditional textbooks is cost savings to students and the ability of all students to have access to the course materials on the first day of class. Studies have investigated faculty and student perceptions of open course materials, and most have had positive experiences with them. Several studies have indicated that students in courses using OER either achieved the same learning outcomes or show improved learning outcomes compared to courses that required traditional textbooks. This paper describes the use of OER and other no-cost digital materials in an undergraduate heat and mass transfer course, as well as the development of instructor-created videos. The main resources include an electronic textbook available at no charge and openly licensed videos. Compared to a previous offering of the course, there was a statistically significant improvement in course performance on two module-level outcomes. A survey at the end of the course indicated that students found the no-cost digital textbook to be about the same quality as or better than the quality of the textbooks in their other courses. Overall, students reported using the textbook in this course more frequently than textbooks in a typical course.