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- Canola oil (2)
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- Steel -- Microstructure (2)
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- Inductively coupled plasma chemical vapor deposition (ICPCVD) (1)
- Laminated metals (1)
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- Locomotion -- Computer simulation (1)
- Mechanical wear -- Testing (1)
- Plunge Depth Control (1)
- Residual stresses -- Measurement (1)
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Articles 1 - 13 of 13
Full-Text Articles in Engineering
Contamination Of Coupling Glass And Performance Evaluation Of Protective System In Vacuum Laser Beam Welding, Yongki Lee, Jason Cheon, Byung-Kwon Min, Cheolhee Kim
Contamination Of Coupling Glass And Performance Evaluation Of Protective System In Vacuum Laser Beam Welding, Yongki Lee, Jason Cheon, Byung-Kwon Min, Cheolhee Kim
Mechanical and Materials Engineering Faculty Publications and Presentations
Vacuum laser beam welding enables deeper penetration depth and welding stability than atmospheric pressure laser welding. However, contaminated coupling glass caused by welding fumes in the vacuum space reduces laser transmittance, leading to inconsistent penetration depth. Therefore, a well-designed protective system is indispensable. Before designing the protective system, the contamination phenomenon was quantified and represented by a contamination index, based on the coupling glass transmittance. The contamination index and penetration depth behavior were determined to be inversely proportional. A cylindrical protective system with a shielding gas supply was proposed and tested. The shielding gas jet provides pressure-driven contaminant suppression and …
Using Thermal Gradient Measurements To Compare Bath Temperature And Agitation Effects On The Quenching Performance Of Palm Oil, Canola Oil And A Conventional Petroleum Oil, Bozidar Matijevic, Bruno F. Canale, Božidar Lišcic, George Totten
Using Thermal Gradient Measurements To Compare Bath Temperature And Agitation Effects On The Quenching Performance Of Palm Oil, Canola Oil And A Conventional Petroleum Oil, Bozidar Matijevic, Bruno F. Canale, Božidar Lišcic, George Totten
Mechanical and Materials Engineering Faculty Publications and Presentations
A proprietary Liscic/Petrofer cylindrical Inconel 600 probe of 50-mm diameter and 200-mm length which was instrumented with three thermocouples on the same radius of the crosssection at the middle of the length was used to determine the differences in quenching performance of two vegetable oils, palm oil and canola oil, and they were compared to a locally produced conventional petroleum oil quenchant. The cooling curves and heat transfer performance of these oils were determined at different bath temperatures and agitation rates. The work was performed at the Quenching Research Centre located at the Faculty for Mechanical Engineering, University of Zagreb, …
X-Ray Determination Of Compressive Residual Stresses In Spring Steel Generated By High-Speed Water Quenching, Diego E. Lozano, George E. Totten, Yaneth Bedolla-Gil, Martha Guerrero-Mata, Marcel Carpio, Gabriela M. Martinez-Cazares
X-Ray Determination Of Compressive Residual Stresses In Spring Steel Generated By High-Speed Water Quenching, Diego E. Lozano, George E. Totten, Yaneth Bedolla-Gil, Martha Guerrero-Mata, Marcel Carpio, Gabriela M. Martinez-Cazares
Mechanical and Materials Engineering Faculty Publications and Presentations
Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core …
Effects Of Steel Type And Sandblasting Pretreatment On The Solid-Liquid Compound Casting Characteristics Of Zinc-Coated Steel/Aluminum Bimetals, Jesik Shin, Taehyeong Kim, Kyoungmook Lim, Hoon Cho, Daeho Yang, Changyeol Jeong, Sung Yi
Effects Of Steel Type And Sandblasting Pretreatment On The Solid-Liquid Compound Casting Characteristics Of Zinc-Coated Steel/Aluminum Bimetals, Jesik Shin, Taehyeong Kim, Kyoungmook Lim, Hoon Cho, Daeho Yang, Changyeol Jeong, Sung Yi
Mechanical and Materials Engineering Faculty Publications and Presentations
Effects of zinc-coated steel type and steel surface sandblasting pretreatment in the solid-liquid compound casting of layered type steel/aluminum bimetals were investigated. The Zn coating behavior and its effects on interfacial microstructure evolution and fracture mechanism were also discussed. The aluminum fluidity in thin plate type flow channels formed by the steel insert and the mold wall primarily depended on the insert surface roughness and secondarily on the wettability. As-galvanized (GI) steel/aluminum bimetal joints showed the bonding strength of 20 MPa and more, while galvannealed (GA) steels showed poor bonding. The interfacial bonding zone consisted of most Al13Fe4, Al8Fe2Si, Al4.5FeSi …
To Burn-In, Or Not To Burn-In: That’S The Question, Ephraim Suhir
To Burn-In, Or Not To Burn-In: That’S The Question, Ephraim Suhir
Mechanical and Materials Engineering Faculty Publications and Presentations
In this paper it is shown that the bathtub-curve (BTC) based time-derivative of the failure rate at the initial moment of time can be considered as a suitable criterion of whether burn-in testing (BIT) should or does not have to be conducted. It is also shown that the above criterion is, in effect, the variance of the random statistical failure rate (SFR) of the mass-produced components that the product manufacturer received from numerous vendors, whose commitments to reliability were unknown, and their random SFR might vary therefore in a very wide range, from zero to infinity. A formula for the …
Parallelized Particle Swarm Optimization To Estimate The Heat Transfer Coefficients Of Palm Oil, Canola Oil, Conventional, And Accelerated Petroleum Oil Quenchants, Zoltán Fried, Imre Felde, Rosa L. Simencio Otero, Jônatas M. Viscaino, George E. Totten, Lauralice Canale
Parallelized Particle Swarm Optimization To Estimate The Heat Transfer Coefficients Of Palm Oil, Canola Oil, Conventional, And Accelerated Petroleum Oil Quenchants, Zoltán Fried, Imre Felde, Rosa L. Simencio Otero, Jônatas M. Viscaino, George E. Totten, Lauralice Canale
Mechanical and Materials Engineering Faculty Publications and Presentations
An inverse solver for the estimation of the temporal-spatial heat transfer coefficients (HTC), without using prior information of the thermal boundary conditions, was used for immersion quenching into palm oil, canola oil, and two commercial petroleum oil quenchants. The particle swarm optimization (PSO) method was used on near-surface temperature-time cooling curve data obtained with the so-called Tensi multithermocouple, and a 12.5 by 45 mm Inconel 600 probe. The fitness function to be minimized by a PSO approach is defined by the deviation of the measured and calculated cooling curves. The PSO algorithm was parallelized and implemented on a graphics accelerator …
Monitored Indoor Environmental Quality Of A Mass Timber Office Building: A Case Study, Jason Stenson, Suzanne L. Ishaque, Aurélie Laguerre, Andrew Loia, Georgia Maccrone, Ignace Mugabo, Dale Northcutt, Mariapaola Riggio, Andre Barbosa, Elliott T. Gall, Kevin Van Den Wymelenberg
Monitored Indoor Environmental Quality Of A Mass Timber Office Building: A Case Study, Jason Stenson, Suzanne L. Ishaque, Aurélie Laguerre, Andrew Loia, Georgia Maccrone, Ignace Mugabo, Dale Northcutt, Mariapaola Riggio, Andre Barbosa, Elliott T. Gall, Kevin Van Den Wymelenberg
Mechanical and Materials Engineering Faculty Publications and Presentations
A broad range of building performance monitoring, sampling, and evaluation was conducted periodically after construction and spanning more than a year, for an occupied office building constructed using mass timber elements such as cross-laminated timber (CLT) floor and roof panels, as well as glue-laminated timber (GLT) beams and columns. This case study contributes research on monitoring indoor environmental quality in buildings, describing one of the few studies of an occupied mass timber building, and analyzing data in three areas that impact occupant experience: indoor air quality, bacterial community composition, and floor vibration. As a whole, the building was found to …
Simulation To Fabrication—Understanding The Effect Of Niaucu Alloy Catalysts For Controlled Growth Of Graphene At Reduced Temperature, Huahan Zhan, Bin Jiang, Otto Zietz, Samuel Olson, Jun Jiao
Simulation To Fabrication—Understanding The Effect Of Niaucu Alloy Catalysts For Controlled Growth Of Graphene At Reduced Temperature, Huahan Zhan, Bin Jiang, Otto Zietz, Samuel Olson, Jun Jiao
Mechanical and Materials Engineering Faculty Publications and Presentations
It is a significant challenge to grow large-scale, high quality, monolayer graphene at low temperature for the applications in industry, especially for the complementary metal oxide semiconductor fabrication process. To overcome this difficulty, we simulated the decomposition of acetylene (C2H2) on (100) surfaces of primarily nickel (Ni) catalysts with small mol fractions of gold (Au) and copper (Cu), using a 4 × 4 × 4 periodic supercell model. Based on the calculation of the reaction energies to decompose the C-H or C≡C bonds on different catalyst surfaces, a differential energy is proposed to clearly scale the decomposition difficulties such that …
Plasma-Enhanced Chemical Vapor Deposition Of Acetylene On Codeposited Bimetal Catalysts Increasing Graphene Sheet Continuity Under Low-Temperature Growth Conditions, Joshua Tracy, Otto Zietz, Samuel Olson, Jun Jiao
Plasma-Enhanced Chemical Vapor Deposition Of Acetylene On Codeposited Bimetal Catalysts Increasing Graphene Sheet Continuity Under Low-Temperature Growth Conditions, Joshua Tracy, Otto Zietz, Samuel Olson, Jun Jiao
Mechanical and Materials Engineering Faculty Publications and Presentations
Here, we report a novel method for low-temperature synthesis of monolayer graphene at 450 °C on a polycrystalline bimetal Ni-Au catalyst. In this study, low-temperature chemical vapor deposition synthesis of graphene was performed at 450 °C on codeposited Ni-Au which shows successful monolayer graphene formation without an extra annealing process. The experimental results suggest that electron beam codeposition of bimetal catalyst is the key procedure that enables the elimination of the pre-growth high-temperature annealing of the catalyst prior to graphene synthesis, an indispensable process, used in previous reports. The formation was further improved by plasma-assisted growth in which the inductively …
Neuromechanical Model Of Rat Hindlimb Walking With Two-Layer Cpgs, Kaiyu Deng, Nicholas Szczecinski, Dirk Arnold, Emanuel Andrada, Martin Fischer, Roger Quinn, Alexander J. Hunt
Neuromechanical Model Of Rat Hindlimb Walking With Two-Layer Cpgs, Kaiyu Deng, Nicholas Szczecinski, Dirk Arnold, Emanuel Andrada, Martin Fischer, Roger Quinn, Alexander J. Hunt
Mechanical and Materials Engineering Faculty Publications and Presentations
This work demonstrates a neuromechanical model of rat hindlimb locomotion undergoing nominal walking with perturbations. In the animal, two types of responses to perturbations are observed: resetting and non-resetting deletions. This suggests that the animal locomotor system contains a memory-like organization. To model this phenomenon, we built a synthetic nervous system that uses separate rhythm generator and pattern formation layers to activate antagonistic muscle pairs about each joint in the sagittal plane. Our model replicates the resetting and non-resetting deletions observed in the animal. In addition, in the intact (i.e., fully afferented) rat walking simulation, we observe slower recovery after …
Performance Of Plunge Depth Control Methods During Friction Stir Welding, Jinyoung Yoon, Cheolhee Kim, Sehun Rhee
Performance Of Plunge Depth Control Methods During Friction Stir Welding, Jinyoung Yoon, Cheolhee Kim, Sehun Rhee
Mechanical and Materials Engineering Faculty Publications and Presentations
Friction stir welding is a preferred solid state welding process for Al/Fe joints, and in friction stir lap welding, the plunge depth is the most critical parameter for joint strength. We compared three plunge depth control methods, namely conventional position control, offset position control, and deflection compensation control in the friction stir lap welding of 3 mm-thick Al 5083-O alloy over 1.2 mm-thick DP 590 steel. The desired plunge depth was 0.2 mm into the steel sheet. However, the pin did not reach the steel surface under conventional position control due to deflection of the vertical axis of the welding …
Improvement Of The Tribological Characteristics Of Aisi 8620, 8640 And 52100 Steels Through Thermo-Reactive Treatments, Rafael Magalhães Triani, Fábio Edson Mariani, Lucas Fuscaldi De Assis Gomes, Pedro Gabriel Bonella De Oliveira, George E. Totten, Luiz Carlos Casteletti
Improvement Of The Tribological Characteristics Of Aisi 8620, 8640 And 52100 Steels Through Thermo-Reactive Treatments, Rafael Magalhães Triani, Fábio Edson Mariani, Lucas Fuscaldi De Assis Gomes, Pedro Gabriel Bonella De Oliveira, George E. Totten, Luiz Carlos Casteletti
Mechanical and Materials Engineering Faculty Publications and Presentations
The production of vanadium and niobium carbides (VC and NbC) layers on AISI 8620, 8640, and 52100 steels may increase hardness and wear resistance of substrates. Thermochemical treatments were performed at 1000 °C for 2 and 4 h. The characterization of the treated samples was carried out by means of Knoop microhardness tests, “calotest” type microadhesive wear test, layer adhesion test according to VDI 3198 standard, and X-ray diffraction. Compact and uniform layers of VC and NbC were obtained in all treatments, with hardness up to 2500 HK and microadhesive wear resistance far superior to that of the substrates, indicating …
Overview Of Homechem: House Observations Of Microbial And Environmental Chemistry, Delphine K. Farmer, Marina E. Vance, Jon P. D. Abbatt, Andrew Abeleira, Michael R. Alves, Richard Corsi, Peter F. Decarlo, Allen H. Goldstein, Vicki H. Grassian, Lea Hildebrandt Ruiz, Jose L. Jimenez, Tara Kahan, Multiple Additional Authors
Overview Of Homechem: House Observations Of Microbial And Environmental Chemistry, Delphine K. Farmer, Marina E. Vance, Jon P. D. Abbatt, Andrew Abeleira, Michael R. Alves, Richard Corsi, Peter F. Decarlo, Allen H. Goldstein, Vicki H. Grassian, Lea Hildebrandt Ruiz, Jose L. Jimenez, Tara Kahan, Multiple Additional Authors
Mechanical and Materials Engineering Faculty Publications and Presentations
The House Observations of Microbial and Environmental Chemistry (HOMEChem) study is a collaborative field investigation designed to probe how everyday activities influence the emissions, chemical transformations and removal of trace gases and particles in indoor air. Sequential and layered experiments in a research house included cooking, cleaning, variable occupancy, and window-opening. This paper describes the overall design of HOMEChem and presents preliminary case studies investigating the concentrations of reactive trace gases, aerosol particles, and surface films. Cooking was a large source of VOCs, CO2, NOx, and particles. By number, cooking particles were predominantly in the ultrafine mode. Organic aerosol dominated …