Collection of IUPUC Division of Mechanical Engineering Works
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Item Improving the Mechanical and Electrochemical Performance of Additively Manufactured 8620 Low Alloy Steel via Boriding(MDPI, 2023-11) Sabuz, Ezazul Haque; Noor-A-Alam, Mohammed; Haider, Waseem; Shabib, Ishraq; IUPUC Division of Mechanical EngineeringIn this study, mechanical and electrochemical performance of borided additively manufactured (AM) and wrought 8620 low alloy steel were investigated and compared to their bare counterparts. The microstructure of borided 8620 exhibited the presence of FeB and Fe2B phases with a saw tooth morphology. Both AM and wrought samples with boride layers showed a similar performance in hardness, wear, potentiodynamic polarization (PD), electrochemical impedance spectroscopy (EIS), and linear polarization resistance (LPR) experiments. However, borided steels exhibited about an 8-fold increase in Vickers hardness and about a 6-fold enhancement in wear resistance compared to bare ones. Electrochemical experiments of borided specimens (both AM and wrought) in 0.1 M Na2S2O3 + 1 M NH4Cl solution revealed a 3–6-fold lower corrosion current density, about a 6-fold higher charge transfer resistance, and about a 6-fold lower double-layer capacitance, demonstrating an improved corrosion resistance compared to their bare counterparts. Post-corrosion surface analysis revealed the presence of thick sulfide and oxide layers on the bare steels, whereas dispersed corrosion particles were observed on the borided samples. The enhanced wear and electrochemical performance of the borided steels were attributed to the hard FeB/Fe2B layers and the reduced amount of adsorbed sulfur on their surface.Item Specifications Grading in Undergraduate Fluid Mechanics(ASEE, 2023-12) Mendez, Julie; IUPUC Mechanical EngineeringItem Enhancing controlled and uniform degradation of Fe by incorporating Mg and Zn aimed for bio-degradable material applications(Elsevier, 2022-06-01) Maruf, Mahbub Alam; Noor-A-Alam, Mohammed; Haider, Waseem; Shabib, Ishraq; IUPUC Mechanical EngineeringIn this study, combinatorial development of three nanostructured thin film systems, i.e., Fe87Mg9Zn4 (FMZ-1), Fe74Mg19Zn7 (FMZ-2), and Fe60Mg30Zn10 (FMZ-3), are employed via magnetron sputtering and their degradation pattern is studied in Phosphate Buffered Saline (PBS) solution. Controlled and uniform degradation of Fe is observed with the addition of Mg and Zn, which are crucial for temporary biodegradable implants. The structural characterization of the three samples demonstrates a crystalline structure of Fe87Mg9Zn4, a partially amorphous structure of Fe74Mg19Zn7, and a substitutional solid solution of bcc-Fe-Mg in Fe60Mg30Zn10 sample. Potentiodynamic polarization test reveals higher degradation tendency with the addition of Mg and Zn in the samples compared to pure Fe, as validated by more negative corrosion potentials and higher corrosion current densities. Samples with higher Mg and Zn contents (FMZ-2 and FMZ-3) exhibiting lower charge transfer resistance, as extracted from electrochemical impedance spectroscopy (EIS), also indicates higher corrosion rate compared to Pure Fe. Time-dependent EIS demonstrates gradual decrease in impedance values, representing controlled degradation of the samples upon exposure in PBS solution. Scanning Electron Microscopy (SEM) confirms uniform degradation pattern of FMZ-2 and FMZ-3 samples compared to FMZ-1 after 12 h and 24 h immersion in PBS solution. Finally, the X-ray Photoelectron Spectroscopy (XPS) depicts the formation of oxides, hydroxides, and phosphates of Fe, Mg, and Zn as corrosion products. The higher degradation tendency of the co-sputtered samples is ascribed to the combined role of chemical composition and non-equilibrium nanostructures.Item Construction and Use of a Concept Map in an Undergraduate Dynamics Class(ASEE PEER, 2022-08-23) Noor-A-Alam, Mohammed; Medez, Julie; IUPUC EngineeringWhile the use of technology in education has been rapidly increasing worldwide, the diversity and availability of information and study materials have been increasing at an even faster rate. However, presenting and explaining key course concepts in an effective and organized manner, as well as involving students in interactive learning experiences, are still key parts of teaching in higher education, more specifically, in achieving the educational objectives in the fundamental courses of science and engineering programs. Keeping this in prime consideration, the use of concept maps in basic engineering courses has been very effective and has gained growing attention in recent years. This work studied the use of a concept map in an undergraduate dynamics class. A two-phase hierarchical approach was used to construct two concept maps which were then demonstrated in the beginning of the course to allow students to see the key points of the entire course. The concept maps took the form of trees, with topics branching up from two broad topic areas at the bottom: dynamics of particles and dynamics of rigid bodies. The entire tree was climbed up as the course progressed. The students were asked to build their own concept map at the end of the semester with the goal of stimulating creativity as delineated by constructivism in contemporary pedagogy. A survey was carried out at the end of the course to study student perceptions of using the concept map. While students expressed different opinions on several questions, 100% of the participant students responded “I agree” to the survey item “The concept map was a useful resource for in-class activities”.Item Intentional Use of the Learning Management System: A Case Study in Self-Regulatory Behaviors in a Blended Undergraduate Thermodynamics Course(ASEE, 2021) Mendez, Julie; IUPUC Division of Mechanical EngineeringIn a blended undergraduate thermodynamics course, affordances within a learning management system (LMS) were used to highlight student learning outcomes, require foundational course content to be completed before attempting more complex topics, provide mastery-oriented feedback, allow students to track their progress, and promote metacognitive reflection. This paper describes the use of these options within the Canvas LMS. Additionally, this study investigated whether student self-regulatory behaviors changed during the course. Students were asked to complete a survey about their metacognitive self-regulatory activities related to studying for this course. The first survey was completed during the fifth week of the course, after most students had completed two reflection assignments. The same survey questions were administered a second time, during the final two weeks of the course. Survey results suggest some increase in student self-regulatory behaviors during the course. These results suggest that, near the end of the course, students were more likely to set study goals for themselves.Item Instructor and Student Experiences with In-Class Polling Options(Purdue University, 2019) Mendez, Julie; IUPUC Division of Mechanical EngineeringActive learning pedagogy has been shown to improve student performance in engineering courses. One active learning technique is Peer Instruction, where students individually answer a poll question, and discuss answer choices with a classmate before answering the same question again. There are various options to conduct in-class polling, from low-tech options, such as holding up fingers or a colored card, to more costly digital technologies, such as commercial platforms that require a dedicated device or a student’s own mobile device. Previous studies have indicated that the pedagogy matters more than the platform or technology used to conduct polling. However, different platforms allow for different affordances not present in some low-tech options. The high-tech options afford some benefits, including being able to ask questions other than multiple choice, such as open response. The purpose of this study is to gain insight into student preferences and to explore benefits and disadvantages of the different platforms from an instructor prospective. Two groups of students were surveyed: one group who completed a course using Plickers, a low-tech system, and another group from two different courses who used the Top Hat Classroom application on their mobile devices. The survey results indicated that the students had a mostly positive experience with each platform. Benefits and drawbacks from an instructor perspective are described.Item Development of a Hybrid Heat and Mass Transfer Course(ASME, 2018-11) Mendez, Julie; IUPUC Division of Mechanical EngineeringThis work describes the development of a hybrid junior-level 4-credit-hour heat and mass transfer course. The lecture portion of the course was developed as approximately 80% online. The students and instructor met in person for the lecture portion of the course once every other week for 50 minutes, with the remaining activities completed online. The laboratory portion of the course remained in the traditional face-to-face format. Specifications grading was used to determine final course grades. This paper will describe the course structure, types of assignments, and use of face-to-face class time. Student performance in the hybrid course is compared to previous student performance in the same course taught in a face-to-face format. Student feedback and instructor observations are shared.Item Standards-Based Specifications Grading in a Hybrid Course(ASEE, 2018-06) Mendez, Julie; IUPUC Division of Mechanical EngineeringStandards-based grading is being used increasingly in engineering courses in place of a traditional points-based grading system. Benefits of standards-based grading include clearly matching course assessments to the learning objectives and putting more focus on learning instead of grades. In specifications grading, students are given detailed requirements with all assignments, which are graded pass/fail. The course grade is based on the number of assignments successfully completed. As more undergraduate courses are offered in online or hybrid formats, there is little documentation of the use of standards-based grading or specifications grading in these course delivery methods in engineering. This work describes the implementation of standards-based specifications grading (SBSG) in a hybrid (approximately 80% online) undergraduate thermodynamics course.Item Standards-Based Specifications Grading in Thermodynamics(ASEE, 2018-04) Mendez, Julie; IUPUC Division of Mechanical Engineering