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Full-Text Articles in Engineering

Economic Feasibility Analysis Of Variable-Speed Pumps By Simulating 15 Multiple Water Distribution Systems, Conrad B. Truettner, Brian D. Barkdoll Apr 2022

Economic Feasibility Analysis Of Variable-Speed Pumps By Simulating 15 Multiple Water Distribution Systems, Conrad B. Truettner, Brian D. Barkdoll

Michigan Tech Publications

The UN Sustainability Goals address measures to reduce environmental pollution. Water distribution systems (WDSs) use electric energy, which pollutes the atmosphere through, at least partly, the burning of coal. This study simulates, through modeling, variable-speed pumps (VSPs) on 15 different real WDSs on the network solver EPANET and analyzes the payback period. An algorithm is introduced here to select the optimal pump speed pattern to save the most energy while satisfying the constrain of sufficient pressure at all times and all locations. It was found that five of the 15 systems operated unsuccessfully using a VSP, due to the VSP …


Frequency Domain Measurements Of Melt Pool Recoil Force Using Modal Analysis, Tristan Cullom, Cody Lough, Nicholas Altese, Douglas Bristow, Robert Landers, Ben Brown, Troy Hartwig, Andrew Barnard, Jason Blough, Kevin Johnson, Edward Kinzel May 2021

Frequency Domain Measurements Of Melt Pool Recoil Force Using Modal Analysis, Tristan Cullom, Cody Lough, Nicholas Altese, Douglas Bristow, Robert Landers, Ben Brown, Troy Hartwig, Andrew Barnard, Jason Blough, Kevin Johnson, Edward Kinzel

Michigan Tech Publications

Recoil pressure is a critical factor affecting the melt pool dynamics during Laser Powder Bed Fusion (LPBF) processes. Recoil pressure depresses the melt pool. When the recoil pressure is low, thermal conduction and capillary forces may be inadequate to provide proper fusion between layers. However, excessive recoil pressure can produce a keyhole inside the melt pool, which is associated with gas porosity. Direct recoil pressure measurements are challenging because it is localized over an area proportionate to the laser spot size producing a force in the mN range. This paper reports a vibration-based approach to quantify the recoil force exerted …


Moving Hands-On Mechanical Engineering Experiences Online: Course Redesigns And Student Perspectives, Jaclyn E. Johnson, Nancy B. Barr Mar 2021

Moving Hands-On Mechanical Engineering Experiences Online: Course Redesigns And Student Perspectives, Jaclyn E. Johnson, Nancy B. Barr

Michigan Tech Publications

Hands-on lab experiences are essential for enabling students to be successful engineers, especially those who identify as kinesthetic learners. This case study describes how a Mechanical Engineering Practice course sequence was redesigned during the COVID-19 emergency transition to remote learning and examines how students responded to these changes. The remote course included videos of Graduate Teaching Assistants conducting data acquisition phases of the practice session to replace hands-on experiments. To understand student perspectives and performance, researchers reviewed approximately 400 reflective essays from Spring 2020 and compared assignment submissions between Fall 2019 and Spring 2020. Results suggest that some students perceived …