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2020

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Articles 451 - 480 of 1398

Full-Text Articles in Mechanical Engineering

The Effect Of Heat Treatment To The Erosion Rate Of Brass Composite, Aminnudin Aminnudin, Solichin Solichin Jul 2020

The Effect Of Heat Treatment To The Erosion Rate Of Brass Composite, Aminnudin Aminnudin, Solichin Solichin

Journal of Mechanical Engineering Science and Technology (JMEST)

Brass composites can be improved their mechanical properties by the heat treatment process. The improvement of the mechanical properties of this technique is expected to increase the resistance of the composite to erosion that occurs in the environment of flow water. Brass composites used are compositeswith fly ash 5, 10, 15, and 20%. The heat treatment process was carried out using electric furnace withoutprotective gas. Composite heat up to 350°C and 400°C for 30 min. and quenching with water. Before and after the erosion test, the weight of the test specimen was weighed with analytical scales. The treatment process affects …


Performance Enhancement Of Shell And Tube Heat Exchanger On Parallel Flow With Single Segmental Baffle, Avita Ayu Permanasari, Poppy Puspitasari, Sukarni Sukarni, Retno Wulandari Jul 2020

Performance Enhancement Of Shell And Tube Heat Exchanger On Parallel Flow With Single Segmental Baffle, Avita Ayu Permanasari, Poppy Puspitasari, Sukarni Sukarni, Retno Wulandari

Journal of Mechanical Engineering Science and Technology (JMEST)

The shell and tube heat exchanger was a tool to exchange the heat energy between fluids with different temperatures that occurred through direct or indirect contact. The energy exchange in fluids could be occurred with the same phase (liquid to liquid or gas to gas) or two fluids with different phase. To date, the process of heat transfer in the industrial field was crucial in machine work. Therefore, there were studies directed to optimize and develop the function and thermal performance of a heat exchanger by adding Baffles to the side of the shell. Vortex flow that occurs with the …


The Effect Of Solution Treatment Temperature And Quenching Media Variation In Heat Treatment Process Cu-Zn-Al Shape Memory Alloys On Shape Memory Effect And Microstructures, Wikan Jatimurti, Monica Gayatri K, Mavindra Ramadhani, Rochman Rochiem Jul 2020

The Effect Of Solution Treatment Temperature And Quenching Media Variation In Heat Treatment Process Cu-Zn-Al Shape Memory Alloys On Shape Memory Effect And Microstructures, Wikan Jatimurti, Monica Gayatri K, Mavindra Ramadhani, Rochman Rochiem

Journal of Mechanical Engineering Science and Technology (JMEST)

Shape memory alloys (SMAs) are metal alloys with a reversible ability to recover their shape at a certain temperature after being deformed. This ability referred to as Shape Memory Effect (SME). The application of SMAs such as Ni-Ti and Cu-Zn-Al alloys usually used on automotive, biomedical, etc. The commonly used SMA is Ni-Ti because of its superior SME properties than Cu-Zn-Al, even though the price is quite higher. The SME of Cu-Zn-Al might be improved by increasing the presence of the martensite phase in its microstructure by heat treatment. The heat treatment process given to Cu-21Zn-5Al alloy is a homogenizing, …


Wavelength Decomposition Of Hybrid Additive Manufacturing Power Signals And Their Relationship With Surface Integrity, Xingtao Wang Jul 2020

Wavelength Decomposition Of Hybrid Additive Manufacturing Power Signals And Their Relationship With Surface Integrity, Xingtao Wang

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Additive Manufacturing (AM) has been a promising manufacturing technology in industrial applications and gained a massive amount of attention from researchers all over the world. Directed Energy Deposition (DED) is an AM process in which focused thermal energy is used to fuse materials by melting as they are deposited. One of the most significant challenges involved in current metal AM processes is improving repeatability and consistency. Substantial effort has already been invested in this area of research.

In this dissertation, a milling tool not only played a role in subtractive manufacturing but also acted as a method of monitoring the …


Experimental Investigation Of The Wind Energy Harvesting Potential Of A Stand-Alone Piezoelectric Strip, Phillip Christopher Scott Jul 2020

Experimental Investigation Of The Wind Energy Harvesting Potential Of A Stand-Alone Piezoelectric Strip, Phillip Christopher Scott

Mechanical Engineering ETDs

The purpose of the study was to investigate the feasibility of harvesting wind energy on a small scale in residential areas. The method investigated was the initiation of movement-induced excitation (MIE), a type of aeroelastic flutter, within samples of polyvinylidine fluoride (PVDF), a piezoelectric polymer. Single samples of PVDF were secured in a wind tunnel and sample voltage was measured over a broad range of wind speeds. Power was calculated then via the addition of ohmic resistance matched to the magnitude of the capacitive impedances of the samples. The geometry of the PVDF samples studied was maintained as a simple …


Systems Thinking In Jaw Crusher Analysis, А. Artikov, L. Akobirova, Z. Akbarhodjaev Jul 2020

Systems Thinking In Jaw Crusher Analysis, А. Artikov, L. Akobirova, Z. Akbarhodjaev

Technical science and innovation

It provides information on the method of system thinking, where the analysis of the crusher for grinding solid materials shows four hierarchical structure of the object - the jaw crusher. For a particle - a piece of material at the lowest hierarchical level, the influence of the infrastructure of the material and object on the stochastic grinding process is considered, which is characterized by probabilistic mathematical models. Moving to higher hierarchical levels, computer models of deterministic processes in the material and the crusher are given. It is preliminary shown that increasing the grinding ratio increases the efficiency of the material …


Optimizing Power Consumption Of Freight Railroad Bearings Using Laboratory Experimental Data, Carlos E. Lopez Iii, Constantine Tarawneh, Arturo A. Fuentes, Harry Siegal Jul 2020

Optimizing Power Consumption Of Freight Railroad Bearings Using Laboratory Experimental Data, Carlos E. Lopez Iii, Constantine Tarawneh, Arturo A. Fuentes, Harry Siegal

Mechanical Engineering Faculty Publications

Based on projected freight truck fuel efficiency, freight railroad and equipment suppliers need to identify, evaluate and implement technologies and/or operating practices to maintain traditional railroad economic competitiveness. The railway industry uses systems that record the total energy efficiency of a train but not energy efficiency or consumption by components. Lowering the energy consumption of certain train components will result in an increase in its overall energy efficiency, which will yield cost benefits for all the stakeholders. One component of interest is the railroad bearing whose power consumption varies depending on several factors that include railcar load, train speed, condition …


Estimating The Inner Ring Defect Size And Residual Service Life Of Freight Railcar Bearings Using Vibration Signatures, Jennifer Lima, Constantine Tarawneh, Jesse Aguilera, Jonas Cuanang Jul 2020

Estimating The Inner Ring Defect Size And Residual Service Life Of Freight Railcar Bearings Using Vibration Signatures, Jennifer Lima, Constantine Tarawneh, Jesse Aguilera, Jonas Cuanang

Mechanical Engineering Faculty Publications

There are currently two primary wayside detection systems for monitoring the health of freight railcar bearings in the railroad industry: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). TADS™ uses wayside microphones to detect and alert the train operator of high-risk defects. However, many defective bearings may never be detected by TADS™ since a high-risk defect is a spall which spans about 90% of a bearing’s raceway, and there are less than 30 systems in operation throughout the United States and Canada. HBDs sit on the side of the rail-tracks and use non-contact infrared sensors to …


Dynamic Effects Of Inertial Particles On The Wake Recovery Of A Model Wind Turbine, Sarah E. Smith Jul 2020

Dynamic Effects Of Inertial Particles On The Wake Recovery Of A Model Wind Turbine, Sarah E. Smith

Dissertations and Theses

Impacting particles such as rain, dust, and other debris can have devastating structural effects on wind turbines, but little is known about the interaction of such debris within turbine wakes. This study aims to characterize behavior of inertial particles within the turbulent wake of a wind turbine and relative effects on wake recovery. Here a model wind turbine is subjected to varied two-phase inflow conditions, with wind as the carrier fluid (Reλ = 49 - 88) and polydisperse water droplets (26 to 45µm in diameter) at varied concentrations (Φv=0.24 x 10-5 - 1.3 …


Mechanical Engineering News, Georgia Southern University Jul 2020

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

  • ME Faculty Awarded NSF REU Grant


Additive Manufacturing And Characterization Of Agi And Agi–Al2O3 Composite Electrolytes For Resistive Switching Devices, Benjamin J. Brownlee, Lok-Kun Tsui, Karthik Vempati, John B. Plumley, Brian D. Iverson, Thomas L. Peng, Fernando H. Garzon Jul 2020

Additive Manufacturing And Characterization Of Agi And Agi–Al2O3 Composite Electrolytes For Resistive Switching Devices, Benjamin J. Brownlee, Lok-Kun Tsui, Karthik Vempati, John B. Plumley, Brian D. Iverson, Thomas L. Peng, Fernando H. Garzon

Faculty Publications

This work investigates the electrochemical dynamics and performance of additively manufactured composite electrolytes for resistive switching. Devices are comprised of a Ag/AgI–Al2O3/Pt stack, where the solid state electrolyte is additively manufactured using extrusion techniques. AgI–Al2O3 composite electrolytes are characterized by x-ray diffraction and electrochemical impedance spectroscopy. The ionic conductivities of the electrolytes were measured for different concentrations of Al2O3, observing a maximum conductivity of 4.5 times the conductivity of pure AgI for composites with 20 mol. % Al2O3. There was little change in activation energy …


Droplet Ejections During Wet Lab Operations Aboard Spacecraft, Caleb Cushman Turner Jul 2020

Droplet Ejections During Wet Lab Operations Aboard Spacecraft, Caleb Cushman Turner

Dissertations and Theses

The breakup and rupture of liquid bridges, thin films, bubbles, droplets, rivulets, and jets can produce satellite droplets that are subsequently ejected into their surrounding environment. For example, when any solid object is withdrawn from a liquid bath, the formation of an ever-thinning columnar liquid bridge eventually ruptures along the axis of the bridge. When rupture occurs under typical pipetting conditions the dynamics governing the rupture almost always produce at a minimum a satellite droplet. When these droplets occur they are often too small and too fast to be observed by the human eye. In a terrestrial environment they are …


Study On The Chemical And Mechanical Stability Of Polymer Nanofluidic Biosensors, Dae Won Kim Jul 2020

Study On The Chemical And Mechanical Stability Of Polymer Nanofluidic Biosensors, Dae Won Kim

LSU Master's Theses

Polymer nanofluidic devices have great potential to replace silicon (Si) and glass-based nanofluidic devices in biomedical applications due to their advantages such as low material and fabrication cost, various physicochemical properties, well-developed surface modification protocol, and low electrical noises for electrical measurements. In nanofluidic sensing applications, single molecules such as DNA are introduced into the fabricated nanochannel or nanopore, measuring their physicochemical properties optically or electrically. The properties of materials for nanofluidic devices have a significant role in the performance of the devices, such as DNA translocation and device stability.

Among several nanoscale fluidic physics, surface charge density is a …


Power Take-Off And Energy Storage System Static Modeling And Sizing For Direct Drive Wave Energy Converter To Support Ocean Sensing Applications, Xiang Zhou, Ossama Abdelkhalik, Wayne Weaver Jul 2020

Power Take-Off And Energy Storage System Static Modeling And Sizing For Direct Drive Wave Energy Converter To Support Ocean Sensing Applications, Xiang Zhou, Ossama Abdelkhalik, Wayne Weaver

Michigan Tech Publications, Part 1

This paper addresses the sizing and design problem of a permanent magnet electrical machine power take-off system for a two-body wave energy converter, which is designed to support ocean sensing applications with sustained power. The design is based upon ground truth ocean data bi-spectrums (swell and wind waves) from Martha’s Vineyard Coastal Observatory in the year 2015. According to the ground truth ocean data, the paper presents the optimal harvesting power time series of the whole year. The electrical machine and energy storage static modeling are introduced in the paper. The paper uses the ground truth ocean data in March …


Advances In Materials Design For All-Solid-State Batteries: From Bulk To Thin Films, Gene Yang, Yuxi Ma, Myoungseok Lee, Evan Helfrick, Dahyun Oh, Dongkyu Lee Jul 2020

Advances In Materials Design For All-Solid-State Batteries: From Bulk To Thin Films, Gene Yang, Yuxi Ma, Myoungseok Lee, Evan Helfrick, Dahyun Oh, Dongkyu Lee

Faculty Publications

All-solid-state batteries (SSBs) are one of the most fascinating next-generation energy storage systems that can provide improved energy density and safety for a wide range of applications from portable electronics to electric vehicles. The development of SSBs was accelerated by the discovery of new materials and the design of nanostructures. In particular, advances in the growth of thin-film battery materials facilitated the development of all solid-state thin-film batteries (SSTFBs)—expanding their applications to microelectronics such as flexible devices and implantable medical devices. However, critical challenges still remain, such as low ionic conductivity of solid electrolytes, interfacial instability and difficulty in controlling …


Comparison Of Plantar Pressure Profile Of Young Adults During Training On Elliptical Devices And Overground Walking: A Pilot Study, Guilherme Manna Cesar, Thad W. Buster, Judith M. Burnfield Jul 2020

Comparison Of Plantar Pressure Profile Of Young Adults During Training On Elliptical Devices And Overground Walking: A Pilot Study, Guilherme Manna Cesar, Thad W. Buster, Judith M. Burnfield

Department of Mechanical and Materials Engineering: Faculty Publications

Background: Elliptical training may offer advantages over other cardiorespiratory exercises for those requiring podiatric care, since its constant double-limb support diminishes recurring high-impact plantar forces while allowing exercise in a functional, upright posture. Unknown is the impact of distinct elliptical models, that can alter user’s body mechanics, on potential variations in plantar pressure patterns.

Purpose: To compare plantar pressure variables while exercising on four ellipticals and walking.

Methods: For this cross-sectional pilot study, plantar pressure data were recorded from ten young adults while exercising on four ellipticals (True, Octane, Life Fitness, SportsArt) and walking overground. One-way repeated measures ANOVA identified …


Plasmon-Phonon Coupling Between Mid-Infrared Chiral Metasurfaces And Molecular Vibrations, Md Shamim Mahmud, Daniel Rosenmann, David A. Czaplewski, Jie Gao, Xiaodong Yang Jul 2020

Plasmon-Phonon Coupling Between Mid-Infrared Chiral Metasurfaces And Molecular Vibrations, Md Shamim Mahmud, Daniel Rosenmann, David A. Czaplewski, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Plasmon-phonon coupling between metamaterials and molecular vibrations provides a new path for studying mid-infrared light-matter interactions and molecular detection. So far, the coupling between the plasmonic resonances of metamaterials and the phonon vibrational modes of molecules has been realized under linearly polarized light. Here, mid-infrared chiral plasmonic metasurfaces with high circular dichroism (CD) in absorption over 0.65 in the frequency range of 50 to 60 THz are demonstrated to strongly interact with the phonon vibrational resonance of polymethyl methacrylate (PMMA) molecules at 52 THz, under both left-handed and right-handed circularly polarized (LCP and RCP) light. The mode splitting features in …


Determination Of Effective Parameters Of Fishnet Metamaterials With Vortex Based Interferometry, Wei Cao, Jie Gao, Xiaodong Yang Jul 2020

Determination Of Effective Parameters Of Fishnet Metamaterials With Vortex Based Interferometry, Wei Cao, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Metamaterials are artificially engineered structures that have unique properties not usually found in natural materials, such as negative refractive index. Conventional interferometry or ellipsometry is generally used for characterizing the optical properties of metamaterials. Here, we report an alternative optical vortex based interferometric approach for the characterization of the effective parameters of optical metamaterials by directly measuring the transmission and reflection phase shifts from metamaterials according to the rotation of vortex spiral interference pattern. The fishnet metamaterials possessing positive, zero and negative refractive indices are characterized with the vortex based interferometry to precisely determine the complex values of effective permittivity, …


A Comparison Of Two Techniques For Center Of Pressure Measurements, Jessica Deberardinis, Conner Neilsen, Daniel E. Lidstone, Janet S. Dufek, Mohamed B. Trabia Jul 2020

A Comparison Of Two Techniques For Center Of Pressure Measurements, Jessica Deberardinis, Conner Neilsen, Daniel E. Lidstone, Janet S. Dufek, Mohamed B. Trabia

Integrated Health Sciences Faculty Research

Introduction: Force platforms and pressure-measuring insoles are the most common tools used for measuring center of pressure. Earlier studies to assess these instruments suffered from limited sample sizes or an inadequate range of participant foot sizes. The purpose of this study was to propose new methods to extract and calculate comparably accurate center of pressure for the Kistler (R) force platform and Medilogic (R) insoles. Methods: Center of pressure data were collected from 65 participants wearing pressure-measuring insoles (six different sizes). Participants walked over consecutive force platforms for three trials while wearing pressure-measuring insoles within socks. Onset force thresholds and …


An Iterative Size Effect Model Of Surface Generation In Finish Machining, Ian S. Brown, Julius M. Schoop Jul 2020

An Iterative Size Effect Model Of Surface Generation In Finish Machining, Ian S. Brown, Julius M. Schoop

Mechanical Engineering Faculty Publications

In this work, a geometric model for surface generation of finish machining was developed in MATLAB, and subsequently verified by experimental surface roughness data gathered from turning tests in Ti-6Al4V. The present model predicts the behavior of surface roughness at multiple length scales, depending on feed, nose radius, tool edge radius, machine tool error, and material-dependent parameters—in particular, the minimum effective rake angle. Experimental tests were conducted on a commercial lathe with slightly modified conventional tooling to provide relevant results. Additionally, the model-predicted roughness was compared against pedigreed surface roughness data from previous efforts that included materials 51CrV4 and AL …


Improving Thermal Conduction Across Cathode/Electrolyte Interfaces In Solid-State Lithium-Ion Batteries By Hierarchical Hydrogen-Bond Network, Jinlong He, Lin Zhang, Ling Liu Jul 2020

Improving Thermal Conduction Across Cathode/Electrolyte Interfaces In Solid-State Lithium-Ion Batteries By Hierarchical Hydrogen-Bond Network, Jinlong He, Lin Zhang, Ling Liu

Mechanical and Aerospace Engineering Student Publications and Presentations

Effective thermal management is an important issue to ensure safety and performance of lithium-ion batteries. Fast heat removal is highly desired but has been obstructed by the high thermal resistance across cathode/electrolyte interface. In this study, self-assembled monolayers (SAMs) are used as the vibrational mediator to tune interfacial thermal conductance between an electrode, lithium cobalt oxide (LCO), and a solid state electrolyte, polyethylene oxide (PEO). Embedded at the LCO/PEO interface, SAMs are specially designed to form hierarchical hydrogen-bond (H-bond) network with PEO. Molecular dynamics simulations demonstrate that all SAM-decorated interfaces show enhanced thermal conductance and dominated by H-bonds types. The …


What Difference Does A Catalyst Make?, Tammy Guthrie, Mike Jackson, Holly Haney Jul 2020

What Difference Does A Catalyst Make?, Tammy Guthrie, Mike Jackson, Holly Haney

High School Lesson Plans

Students will use different catalysts for the decomposition of Hydrogen Peroxide, to determine if different catalysts affect the energy that is generated during the reaction.


Distributed Adaptive State Estimation And Tracking Scheme For Nonlinear Systems Using Active Passive Sensor Networks, Akhilesh Raj, S. Jagannathan, Tansel Yucelen Jul 2020

Distributed Adaptive State Estimation And Tracking Scheme For Nonlinear Systems Using Active Passive Sensor Networks, Akhilesh Raj, S. Jagannathan, Tansel Yucelen

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a novel adaptive neural network (NN) based distributed state estimation scheme for a heterogeneous sensor network (HSN), to estimate the state vector of an unknown nonlinear process/target by using sensed output when the target input remains unknown. The active nodes in the HSN can sense the target output based on the detection range. By using a connected graph, the active nodes will communicate their estimated state vector from their adaptive NN observer to other passive nodes in the neighborhood that cannot sense the target, so that they can estimate the target state vector. Next, a subset of …


Effects Of Zirconia Doping On Additively Manufactured Alumina Ceramics By Laser Direct Deposition, John M. Pappas, Aditya R. Thakur, Xiangyang Dong Jul 2020

Effects Of Zirconia Doping On Additively Manufactured Alumina Ceramics By Laser Direct Deposition, John M. Pappas, Aditya R. Thakur, Xiangyang Dong

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The ability to additively manufacture functional alumina ceramics has the potential to lower manufacturing costs and development time for complex components. In this study, the doping effects of zirconia on laser direct deposited alumina ceramics were investigated. The microstructure of the printed samples was analyzed in terms of grain size and composition distribution. The addition of zirconia was found to accumulate along alumina grain boundaries and resulted in significant grain refinement. The zirconia doping largely reduced crack formation during processing compared to that of pure alumina samples. In the case of 10 wt% zirconia, cracking during deposition was nearly completely …


Magnetically Induced Carrier Distribution In A Composite Rod Of Piezoelectric Semiconductors And Piezomagnetics, Guolin Wang, Jinxi Liu, Wenjie Feng, Jiashi Yang Jul 2020

Magnetically Induced Carrier Distribution In A Composite Rod Of Piezoelectric Semiconductors And Piezomagnetics, Guolin Wang, Jinxi Liu, Wenjie Feng, Jiashi Yang

Department of Mechanical and Materials Engineering: Faculty Publications

In this work, we study the behavior of a composite rod consisting of a piezoelectric semiconductor layer and two piezomagnetic layers under an applied axial magnetic field. Based on the phenomenological theories of piezoelectric semiconductors and piezomagnetics, a one-dimensional model is developed from which an analytical solution is obtained. The explicit expressions of the coupled fields and the numerical results show that an axially applied magnetic field produces extensional deformation through piezomagnetic coupling, the extension then produces polarization through piezoelectric coupling, and the polarization then causes the redistribution of mobile charges. Thus, the composite rod exhibits a coupling between the …


Monocular Visual Inertial Odometry Using Learning-Based Methods, Yuan Tian Jul 2020

Monocular Visual Inertial Odometry Using Learning-Based Methods, Yuan Tian

Doctoral Dissertations and Master's Theses

Precise pose information is a fundamental prerequisite for numerous applications in robotics, Artificial Intelligent and mobile computing. Many well-developed algorithms have been established using a single sensor or multiple sensors. Visual Inertial Odometry (VIO) uses images and inertial measurements to estimate the motion and is considered a key technology for GPS-denied localization in the real world and also virtual reality and augmented reality.

This study develops three novel learning-based approaches to Odometry estimation using a monocular camera and inertial measurement unit. The networks are well-trained on standard datasets, KITTI and EuROC, and a custom dataset using supervised, unsupervised and semi-supervised …


Towards A Cyber-Physical Manufacturing Cloud Through Operable Digital Twins And Virtual Production Lines, Md Rakib Shahriar Jul 2020

Towards A Cyber-Physical Manufacturing Cloud Through Operable Digital Twins And Virtual Production Lines, Md Rakib Shahriar

Graduate Theses and Dissertations

In last decade, the paradigm of Cyber-Physical Systems (CPS) has integrated industrial manufacturing systems with Cloud Computing technologies for Cloud Manufacturing. Up to 2015, there were many CPS-based manufacturing systems that collected real-time machining data to perform remote monitoring, prognostics and health management, and predictive maintenance. However, these CPS-integrated and network ready machines were not directly connected to the elements of Cloud Manufacturing and required human-in-the-loop. Addressing this gap, we introduced a new paradigm of Cyber-Physical Manufacturing Cloud (CPMC) that bridges a gap between physical machines and virtual space in 2017. CPMC virtualizes machine tools in cloud through web services …


Casimir Effect On Amplitude-Frequency Response Of Parametric Resonance Of Electrostatically Actuated Nems Cantilever Resonators, Dumitru Caruntu, Christian A. Reyes Jul 2020

Casimir Effect On Amplitude-Frequency Response Of Parametric Resonance Of Electrostatically Actuated Nems Cantilever Resonators, Dumitru Caruntu, Christian A. Reyes

Mechanical Engineering Faculty Publications

This paper deals with the effect of Casimir force on the amplitudefrequency response of parametric resonance of electrostatically actuated nanoresonators. The resonator is actuated by using an electrostatic force to include a f irst order fringe correction. Casimir force and viscous damping force are included in the model, as well. Both electrostatic and Casimir forces are nonlinear. The behavior of the resonator is investigated using two methods, the Method of Multiple Scales (MMS) for a Reduced Order Model (ROM) using one mode of vibration, and numerical integration of ROMs using up to five modes of vibration. ROM is based on …


Implementation Of Cholesteric Liquid Crystals In Fibrous Based Membranes, Ydana Yanell Virgen Gracia Jul 2020

Implementation Of Cholesteric Liquid Crystals In Fibrous Based Membranes, Ydana Yanell Virgen Gracia

Theses and Dissertations

The project consists of an investigation of optical sensors. On this project, the main focus was to implement materials that had properties such as thermochromism, piezochromism, and be able to detect volatile organic compounds with a color change response. The materials selected for this project were Cholesteric Liquid Crystals (CLCs) in different combinations and ratios. There were also four different methods using Forcespinning © technology to apply the CLCs into a polymer matrix; these were, In-Solution, Dip Coating, Coaxial Spinning, and Emulsion. The best results were given by Dip Coating, but the method with the best viable solution was Coaxial …


Preventing Delayed Cracks In Sus304 Deep Drawn Cups Using Extreme Blank Holding Forces Aided By Nanolubrication, Ibrahim Muhammad Shafiq Jul 2020

Preventing Delayed Cracks In Sus304 Deep Drawn Cups Using Extreme Blank Holding Forces Aided By Nanolubrication, Ibrahim Muhammad Shafiq

Student Works (2020-2029)

This study was to investigate the formation and reformation of delayed cracks of SUS304 cylindrical drawn cups under elevated blank holding force (BHF) from 8~32 kN with 1~3 wt% SiO2 nanolubricants concentrations. The widest crack-free BHF range i.e. from 29 ~ 31 kN was determined for 2 wt% of SiO2 in the experiment. Delayed cracks were also observed below and beyond this BHF range. There was an increment of frictional force at the cup flange region when entering the crack-free BHF range, as proven by the rebound in sidewall thickness, relative intensity of α′-martensite, elongated height and drawing force beyond …