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Full-Text Articles in Engineering

Existence Of A Nonzero Worst-Case Ach For Short-Term Exposure In Ventilated Indoor Spaces, K. A. Krishnaprasad, ‪Nadim Zgheib, K. Choudhary, M. Y. Ha, C. Y. Choi, K. S. Bang, S. Jang, S. Balachandar Mar 2024

Existence Of A Nonzero Worst-Case Ach For Short-Term Exposure In Ventilated Indoor Spaces, K. A. Krishnaprasad, ‪Nadim Zgheib, K. Choudhary, M. Y. Ha, C. Y. Choi, K. S. Bang, S. Jang, S. Balachandar

Mechanical Engineering Faculty Publications and Presentations

A well-ventilated room is essential to reduce the risk of airborne transmission. As such, the scientific community sets minimum limits on ventilation with the idea that increased ventilation reduces pathogen concentration and thus reduces the risk of transmission. In contrast, the upper limit on ventilation is usually determined by human comfort and the need to reduce energy consumption. While average pathogen concentration decreases with increased ventilation, local concentration depends on multiple factors and may not follow the same trend, especially within short exposure times over large separation distances. Here, we show through experiments and high-fidelity simulations the existence of a …


Impact Of Welding Parameters In The Porosity Of A Dissimilar Welded Lap Joint Of Cp800-Xpf1000 Steel Weldment By Gmaw-P, Julio Cesar Garcia-Guerrero, Francisco Fernando Curiel-López, Víctor Hugo López-Morelos, Jaime Taha-Tijerina, Teresita Jesus Sánchez-Cruz, Maria Del Carmen Ramirez-Lopez, Eduardo Cortes-Carillo, Miguel Angel Quinones-Salinas Mar 2024

Impact Of Welding Parameters In The Porosity Of A Dissimilar Welded Lap Joint Of Cp800-Xpf1000 Steel Weldment By Gmaw-P, Julio Cesar Garcia-Guerrero, Francisco Fernando Curiel-López, Víctor Hugo López-Morelos, Jaime Taha-Tijerina, Teresita Jesus Sánchez-Cruz, Maria Del Carmen Ramirez-Lopez, Eduardo Cortes-Carillo, Miguel Angel Quinones-Salinas

Informatics and Engineering Systems Faculty Publications and Presentations

The use of the orthogonal array L4 allows a determination of the effect between the welding parameters peak current (Ip), background current (Ib) and frequency (f) on the porosities in a dissimilar welded lap joint of CP800 and XPF1000 steel weldment by the gas metal arc welding process with the transfer pulsed mode. According to the results, modifications in the welding parameters affect the heat input during welding. A heat input higher than 0.30 KJ/mm generates up to 0.32% porosity in the weld metal, while a heat input lower than 0.25 KJ/mm generates up to 28% porosity in the weld …


Characterization Of Microstructural And Mechanical Properties Of 17-4 Ph Stainless Steel By Cold Rolled And Machining Vs. Dmls Additive Manufacturing, Pablo Moreno-Garibaldi, Melvyn Alvarez-Vera, Juan Alfonso Beltrán-Fernández, Rafael Carrera-Espinoza, Héctor Manuel Hdz-García, J. C. Díaz-Guillen, Rita Muñoz-Arroyo, Javier A. Ortega, Paul Molenda Mar 2024

Characterization Of Microstructural And Mechanical Properties Of 17-4 Ph Stainless Steel By Cold Rolled And Machining Vs. Dmls Additive Manufacturing, Pablo Moreno-Garibaldi, Melvyn Alvarez-Vera, Juan Alfonso Beltrán-Fernández, Rafael Carrera-Espinoza, Héctor Manuel Hdz-García, J. C. Díaz-Guillen, Rita Muñoz-Arroyo, Javier A. Ortega, Paul Molenda

Mechanical Engineering Faculty Publications and Presentations

The 17-4 PH stainless steel is widely used in the aerospace, petrochemical, chemical, food, and general metallurgical industries. The present study was conducted to analyze the mechanical properties of two types of 17-4 PH stainless steel—commercial cold-rolled and direct metal laser sintering (DMLS) manufactured. This study employed linear and nonlinear tensile FEM simulations, combined with various materials characterization techniques such as tensile testing and nanoindentation. Moreover, microstructural analysis was performed using metallographic techniques, optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The results on the microstructure for 17-4 PH DMLS stainless steel reveal …


Wire Texture C-Axis Distribution Of Strontium Ferrite/Pa-12 Extruded Filament, Gabriela Espinosa-Rodriguez, Oluwasola Arigbabowo, Jonathan Alvarado, Jitendra Tate, Wilhelmus J. Geerts Feb 2024

Wire Texture C-Axis Distribution Of Strontium Ferrite/Pa-12 Extruded Filament, Gabriela Espinosa-Rodriguez, Oluwasola Arigbabowo, Jonathan Alvarado, Jitendra Tate, Wilhelmus J. Geerts

Mechanical Engineering Faculty Publications and Presentations

The magnetic anisotropy of strontium ferrite (SF)/PA12 filament, a popular hard magnetic ferrimagnetic composites that is used for 3D-printing of permanent magnets, is studied by vibrating sample magnetometry. The studied filaments have a composition of SF/PA-12 thermoplastic composite with a 40% wt.  ratio of SF. SF particles are non-spherical platelets with an average diameter of 1.3 um and a diameter to thickness ratio of 3. Filaments are produced by a twin-screw extruder and have a diameter of 1.5 mm. SEM images show that the SF particles are homogeneously distributed through the filament. VSM measurements on different parts of the filaments …


Tribological Properties Of H-Bn, Ag And Mgo Nanostructures As Lubricant Additives In Vegetable Oils, Victoria Granja, Kollol Sarker Jogesh, Jaime Taha-Tijerina, C. Fred Higgs Iii Feb 2024

Tribological Properties Of H-Bn, Ag And Mgo Nanostructures As Lubricant Additives In Vegetable Oils, Victoria Granja, Kollol Sarker Jogesh, Jaime Taha-Tijerina, C. Fred Higgs Iii

Informatics and Engineering Systems Faculty Publications and Presentations

There exists an ever-growing need for sustainable engineering solutions to improve emission control and the energy efficiency of tribosystems. This study examines the tribological properties of two environmentally friendly vegetable fluids, soybean and sunflower oil, with the addition of three non-toxic nanostructures (h-BN, silver and MgO) at different concentrations. It was found that nanostructures added to vegetable oils at specific concentrations can exhibit good friction reduction and wear preventive properties. The addition of h-BN nanosheets in sunflower oil decreased the coefficient of friction and the wear damage, as measured by the wear scar diameter. Silver and magnesium oxide nanoparticles further …


Assessing The Lubrication Performance Of Sunflower Oil Modified With Montmorillonite Clay (Mmt) Nanoparticles For Industrial Applications, Md Mashfiqur Rahman, Md Abu Sayeed Biswas, Laura Peña-Pará, Demófilo Maldonado- Cortés, Javier A. Ortega Feb 2024

Assessing The Lubrication Performance Of Sunflower Oil Modified With Montmorillonite Clay (Mmt) Nanoparticles For Industrial Applications, Md Mashfiqur Rahman, Md Abu Sayeed Biswas, Laura Peña-Pará, Demófilo Maldonado- Cortés, Javier A. Ortega

Mechanical Engineering Faculty Publications and Presentations

Because of the environmental impact and price volatility, there has been a growing concern about using petroleum-based lubricants. This issue has encouraged research into the development of biodegradable lubricants like vegetable oils. This study assessed the tribological behavior of sunflower oil modified with Montmorillonite nanoclay (MMT) as lubricant additives. A block-on-ring tribometer was used to assess the wear and friction characteristics of the nano-lubricants. A custom-made tapping torque tester was used to evaluate the nano-lubricants in a real-world application. It was found that the volumetric wear, Coefficient of Friction, and torque of the system decreased when MMT nanoparticles were added. …


Graphene Reinforced Pvdf Nanofibers Fabricated With The Forcespinning® Method For Water Desalination Applications, Elmmer A. Vera Alvarado, Md. Abdur Rahman Bin Abdus Salam, Ali Ashraf, Karen Lozano Feb 2024

Graphene Reinforced Pvdf Nanofibers Fabricated With The Forcespinning® Method For Water Desalination Applications, Elmmer A. Vera Alvarado, Md. Abdur Rahman Bin Abdus Salam, Ali Ashraf, Karen Lozano

Mechanical Engineering Faculty Publications and Presentations

Direct contact membrane distillation (DCMD) is a thermally driven energy and cost-efficient desalination technique where low-grade energy from solar or waste heat from plants can be used to recover fresh water from high saline water. The DCMD technique allows both the feed and permeate solutions to be in contact with the membrane, where vapor from the feed gets condensed in the permeate side once it collides with low- temperature water. Polyvinylidene fluoride (PVDF) nanofiber membranes were prepared by the ForceSpinning® method, these were later dip coated in graphene solutions prepared with different solvents. The ForceSpinning® method, unlike electrospinning, operates in …


Modelling Of A Drone To Analyze Dynamic Instabilities With Its Delivery System, Eleazar Marquez, Ivan Luna Feb 2024

Modelling Of A Drone To Analyze Dynamic Instabilities With Its Delivery System, Eleazar Marquez, Ivan Luna

Mechanical Engineering Faculty Publications and Presentations

In the study herein, an alternative mathematical model was developed with the intention of understanding the dynamics associated with the instabilities generated by an UAV and its delivery system, particularly the coupled nonlinearities of the system, and thus provide feedback to optimize drone design. In this regard, a Newton-Euler methodology was adopted to establish the parameters of the equations of motion of the target UAV system, which consisted of a combination of a platform and delivery system operating simultaneously. Specifically, the UAV platform was modelled as a rigid body which accounted for a total of six-degrees-of-freedom, three corresponding to the …


In-Situ Shear Exfoliation Of Graphene From Graphite Polymer Nanocomposites For Lung And Heart Motion, Md Ashiqur Rahman, Md Abdur Rahman Bin Abdus Salam, Ali Ashraf Feb 2024

In-Situ Shear Exfoliation Of Graphene From Graphite Polymer Nanocomposites For Lung And Heart Motion, Md Ashiqur Rahman, Md Abdur Rahman Bin Abdus Salam, Ali Ashraf

Mechanical Engineering Faculty Publications and Presentations

Graphene-based nanocomposites have become attractive for different applications such as energy storage, sensors, biomolecule detection, biomedical, healthcare, and wearable devices due to their unique mechanical, electrical, and thermal properties. However, using commercial graphene for making nanocomposite devices can be expensive, and fabricating nanocomposites can be challenging due to impurities while transferring graphene to elastomer composites. In this study, we used a simple, inexpensive in-situ shear exfoliation method to produce graphene from graphite directly within the elastomer. As the graphene in the elastomer reached beyond its percolation or threshold, electrons hop or tunnel around from one graphene flake to another. So, …


Effect Of Foot Additional Mass On The Clinical Angles Of Knee Extension Exercise, Dumitru I. Caruntu, Alfirio Trejo, Eric Rodriguez, Camila T. Alvarez B Feb 2024

Effect Of Foot Additional Mass On The Clinical Angles Of Knee Extension Exercise, Dumitru I. Caruntu, Alfirio Trejo, Eric Rodriguez, Camila T. Alvarez B

Mechanical Engineering Faculty Publications and Presentations

This study investigates the effect of foot additional mass on the abduction and internal rotation knee angles during knee extension exercise. Three subjects (two male and one female) performed four sets of ten repetitions of the knee extension exercise for the right leg. For the first set, the subject performed the exercise with no additional weight. For each set after, weight was added around the subject’s right foot and the subject was allowed a rest period before beginning the next set. The weights for sets 1, 2, 3, and 4 were 0.00kg (no additional weight) ,0.82kg, 1.64kg, and 2.27kg respectively. …


Computational Modelling Of A Triaxial Vibrating Sample Magnetometer, Leo Rodriguez, Arjun Sapkota, Jonathan Alvarado, Jitendra S. Tate, Wilhelmus J. Geerts Feb 2024

Computational Modelling Of A Triaxial Vibrating Sample Magnetometer, Leo Rodriguez, Arjun Sapkota, Jonathan Alvarado, Jitendra S. Tate, Wilhelmus J. Geerts

Mechanical Engineering Faculty Publications and Presentations

Magnetic Field Assisted Additive Manufacturing (MFAAM) enables 3D printing of magnetic materials of various shapes which exhibit a complex anisotropy energy surface containing contributions generated from different origins such as sample, particle, and agglomerate shape anisotropy, flow and field induced anisotropy, and particle crystal anisotropy. These novel magnet shapes require the need to measure the x, y, and z components of the magnetic dipole moment simultaneously to fully understand the magnetic reversal mechanism and unravel the complex magnetic anisotropy energy surface of 3D printed magnetic composites. This work aims to develop a triaxial vibrating sample magnetometer (VSM) by adding a …