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Articles 10051 - 10080 of 30047

Full-Text Articles in Mechanical Engineering

Nano Fab Lab 63, Brian K. Deemer, Josh Clemons, Nick Brodine, Delaney Fitzsimmons Jun 2019

Nano Fab Lab 63, Brian K. Deemer, Josh Clemons, Nick Brodine, Delaney Fitzsimmons

Mechanical Engineering

Lawrence Livermore National Laboratories (LLNL) has several steps in the production process for ceramic nanofiber tubes that they would like to improve - electrospinning, cutting, rolling, sealing and heat treating. We undertook the challenge to deliver LLNL with a semi-automated process that efficiently integrates the steps of cutting, rolling, and sealing to save time and improve control over end dimensions. In this document, we discuss the technical background of the manufacturing steps currently followed to create nanofiber tubes, identify which steps are incorporated in our prototype and explain how they will interface with one another, define the design requirements, present …

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Atmospheric Water Harvesting: An Experimental Study Of Viability And The Influence Of Surface Geometry, Orientation, And Drainage, Carson T. Hand Jun 2019

Atmospheric Water Harvesting: An Experimental Study Of Viability And The Influence Of Surface Geometry, Orientation, And Drainage, Carson T. Hand

Master's Theses

Fresh water collection techniques have gained significant attention due to global dwindling of fresh water resources and recent scares such as the 2011-2017 California drought. This project explores the economic viability of actively harvesting water from fog, and techniques to maximize water collection. Vapor compression and thermoelectric cooling based dehumidifier prototypes are tested in a series of experiments to assess water collection capability in foggy environments, and what parameters can increase that capability. This testing shows an approximate maximum collection rate of 1.25 L/kWh for the vapor compression prototype, and 0.32 L/kWh for the thermoelectric cooling prototype; compared to 315 …

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Evaluation Of Tensile Properties For Selective Laser Melted 316l Stainless Steel And The Influence Of Inherent Process Features, Paul Swartz Jun 2019

Evaluation Of Tensile Properties For Selective Laser Melted 316l Stainless Steel And The Influence Of Inherent Process Features, Paul Swartz

Master's Theses

Optimal print parameters for additively manufacturing 316L stainless steel using selective laser melting (SLM) at Cal Poly had previously been identified. In order to further support the viability of the current settings, tensile material characteristics were needed. Furthermore, reliable performance of the as-printed material had to be demonstrated. Any influence on the static performance of parts in the as-printed condition inherent to the SLM manufacturing process itself needed to be identified. Tensile testing was conducted to determine the properties of material in the as-printed condition. So as to have confidence in the experimental results, other investigations were also conducted to …

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Adapted Trailer Hitching System, Joseph Neil Hearn, Maxwell M. Selna, Maximilian D. Cossalter, Eric B. Ringsrud Jun 2019

Adapted Trailer Hitching System, Joseph Neil Hearn, Maxwell M. Selna, Maximilian D. Cossalter, Eric B. Ringsrud

Mechanical Engineering

This report highlights the entire design process of an adapted trailer hitching system for Taylor Morris: a navy veteran and quadruple amputee. This begins with problem definition through customer and product research. Objectives are generated after the problem is defined and the boundary of the project is set. This outcome of the project focuses on modifications/improvements to the vehicle side of the problem and leaves the trailers untouched. Engineering specifications are developed to constrain the concept design direction, which ultimately dictates the outcome of the final design. The final design is used as a basis to manufacture a structural prototype …

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Reduce, Reuse, Reengineer, Neil Ryan Robertson, Anthony James Beers Jun 2019

Reduce, Reuse, Reengineer, Neil Ryan Robertson, Anthony James Beers

Architectural Engineering

Our senior project is a research exploration of renewable energy. We recognized there is a major need in the world for the advancement of green power sources. For our project, we wanted to go beyond what we have learned in our Cal Poly architectural engineering classes and to use some of our own creativity to investigate the possibilities of renewable energy from a structural perspective. The guiding question we asked ourselves was, “as architectural engineering students, how could we shift our world to use more renewable energy?” To start our journey off, was the original inspiration from the work of …

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Modifying Casting Parameters To Improve The High Temperature Ductility Of Investment Cast Nickel-Based Superalloy Pwa 1455, Lars Alexander Hedin, Cole Magnum Introligator Jun 2019

Modifying Casting Parameters To Improve The High Temperature Ductility Of Investment Cast Nickel-Based Superalloy Pwa 1455, Lars Alexander Hedin, Cole Magnum Introligator

Materials Engineering

PCC Structurals, an industry leader in superalloy investment castings, has observed inconsistencies in the stress rupture performance of polycrystalline nickel-based superalloy PWA 1455. PCC has changed their casting parameters to reduce the thermal gradient during cooling but have been unable to correlate these changes with an increase in stress rupture elongation. Metallographic examination of past samples indicated microstructures composed of non- equiaxed dendritic grains with mean diameter of .021 inches along the test axis. A similar study on polycrystalline superalloys has indicated that excessive superheat temperatures above the liquidus can result in large grains identical to those observed, limiting the …

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The Conversion Of Manual Machining Equipment Into Smart, Connected Systems With Real-Time Monitoring And Issue Identification Capabilities, David Lee Williams Jun 2019

The Conversion Of Manual Machining Equipment Into Smart, Connected Systems With Real-Time Monitoring And Issue Identification Capabilities, David Lee Williams

Theses and Dissertations

With the advent of the fourth industrial revolution, information technology and manufacturing systems are merging to form what is now known as Smart Manufacturing. However, with this newer technology being integrated with newer pieces of machining equipment, companies with legacy equipment occasionally are in a bind since these machines were not designed or built with the fundamental components of smart manufacturing systems: unified connectivity, real-time monitoring, and issue identification. The purpose of this research is to provide a solution for converting manual machining equipment into smart systems with these fundamental components of smart manufacturing. The pieces of equipment that were …

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Design, Fabrication And Testing Of A Pressurized Oxy-Coal Reactor Exhaust System, Aaron Bradley Skousen Jun 2019

Design, Fabrication And Testing Of A Pressurized Oxy-Coal Reactor Exhaust System, Aaron Bradley Skousen

Theses and Dissertations

One of the challenges facing engineers is to provide clean, sustainable, affordable and reliable electricity. One of the major pollutants associated with coal combustion is CO2. A proposed technology for efficiently capturing CO2 while producing electricity is pressurized oxy-combustion (POC). The first objective of this work is to design, build and demonstrate an exhaust system for a 20 atmosphere oxy-coal combustor. The second objective of this work is to design and build mounts for a two-color laser extinction method in the POC. The POC reactor enables the development of three key technologies: a coal dry-feed system, a high pressure burner, …

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Frequency Response And Recovery Of Muscles And Effects Of Wrapping The Lower Leg On Surface Velocity Measurements, Cameron David Smallwood Jun 2019

Frequency Response And Recovery Of Muscles And Effects Of Wrapping The Lower Leg On Surface Velocity Measurements, Cameron David Smallwood

Theses and Dissertations

This thesis is comprised of two studies. The objective of the first study was to find the frequency response and stiffness of the biceps brachii muscle group during recovery from exercise induced damage and to determine whether these data could be used to track muscle recovery by correlating changes in the frequency response with changes in muscle stiffness. Stiffness moduli were collected using Shear Wave Elastography (SWE) which were then applied to a proportional first mode frequency analysis. Data were collected for the muscle stiffness and frequency response for fifteen subjects (25.6 +- 4.5). By comparing the proportion of the …

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Dynamic Radiation Heat Transfer Control Through Geometric Manipulation, Rydge Blue Mulford Jun 2019

Dynamic Radiation Heat Transfer Control Through Geometric Manipulation, Rydge Blue Mulford

Theses and Dissertations

The surface area and radiative properties of an object influence the rate of radiative emission from the object's surface and the rate of radiative absorption into the surface. Control of these variables would allow for the radiative heat transfer behavior of the surface to be manipulated in real time. Origami tessellations, being a repeated pattern of linked, dynamic surfaces, provide a framework by which dynamic control of apparent radiative properties and surface area is possible. The panels within a tessellation form cavities whose aspect ratio varies as the device actuates. The cavity effect suggests that the apparent radiative properties of …

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A Numerical Simulation Optimizing Droplet Motion Driven By Electrowetting, Jake M. Lesinski Jun 2019

A Numerical Simulation Optimizing Droplet Motion Driven By Electrowetting, Jake M. Lesinski

Master's Theses

A numerical simulation of electrowetting on a dielectric was performed in COMSOL to grant insight on various parameters that play a critical role in system performance. The specific system being simulated was the Open Drop experiment and the parameters being investigated were the applied voltage, contact angle at the advancing triple point, and droplet overlap onto neighboring actuated electrodes. These parameters were investigated with respect to their effect on droplet locomotion performance. This performance was quantified by the droplets velocity and the dielectrophortic (DEP) force’s magnitude; the DEP force was calculated from integration of the Maxwell Stress Tensor, however, the …

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Redesign Of Cubesat For Beam Charging, Kuba Preis Jun 2019

Redesign Of Cubesat For Beam Charging, Kuba Preis

Industrial and Manufacturing Engineering

This paper is intended to be a study in the applications of the design freedom granted by additive manufacture in the design of a 1U CubeSat frame. The main loads experienced by a CubeSat are structural (during launch) and thermal (solar radiation). Beam charging is an emerging technology which involves charging a CubeSat using a laser beam. In this paper, a CubeSat frame was redesigned to account for the structural loads induced during launch and the thermal loads induced when beam charging. The thermal, weight, design, and structural requirements for a new CubeSat design were derived. The 1U CubeSat frame …

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Commercial Vehicle Research Buggy For Active Driver Assistance Systems, Fernando Mondragon-Cardenas, Nathaniel Mccutcheon Furbeyre, Ricardo Steven Lickiss Tan Iv Jun 2019

Commercial Vehicle Research Buggy For Active Driver Assistance Systems, Fernando Mondragon-Cardenas, Nathaniel Mccutcheon Furbeyre, Ricardo Steven Lickiss Tan Iv

Mechanical Engineering

This is the Final Design Report for Daimtronics, a senior project team sponsored by Professor Charles Birdsong of Cal Poly and by Daimler Trucks North America. This team integrated mechatronic systems into a scale semi-truck chassis using existing mechanical and software systems from three separate Cal Poly senior projects over the recent years: Daimscale, MicroLaren, and ProgreSSIV. The goal was to have a user-friendly platform capable of executing autonomous driving algorithms that are programmable at a high level in Simulink and Robotic Operating System (ROS). Advanced driver assistance and autonomous vehicle algorithms were not within the scope of this project, …

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Gravity Drip Irrigation System, Ryan C. Waldron, Cole R. Presson, Josh L. Plaskett Jun 2019

Gravity Drip Irrigation System, Ryan C. Waldron, Cole R. Presson, Josh L. Plaskett

Mechanical Engineering

A gravity-fed, drip irrigation system prototype has been developed for use in raised garden beds and other small-scale crop irrigation applications. The original developer of the prototype and sponsor of the project, Tina Creel, is seeking to refine it into a functional consumer product through the implementation of technical engineering and standard manufacturing processes. The scope of the project includes the tank support system and supply of water to the sponsors current piping subsystem. It does not include any modifications to the bed, piping system or water tank itself. The target specifications of the system include its load capacity, dimensions, …

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Human Powered Vehicle Trainer, Nicholas Hung Nguyen, Gregory Reece Bridges, Jacinta Garcia, Mitchell Sidney Smith Jun 2019

Human Powered Vehicle Trainer, Nicholas Hung Nguyen, Gregory Reece Bridges, Jacinta Garcia, Mitchell Sidney Smith

Mechanical Engineering

This Final Design Review (FDR) document describes the final design and completed prototype of a Mechanical Engineering senior project team at California Polytechnic State University, San Luis Obispo. The project goal is to create an adjustable human powered vehicle training bike for George Leone that allows a rider to gain confidence with the unique reclined bike geometry ahead of the World Human Powered Speed Challenge at Battle Mountain, Nevada. This document outlines the customer’s needs and technical research performed which together determine the project’s scope and engineering specifications. Next, we present the initial idea generation process and its results, along …

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Adaptive Paddle Board, Alexander Holthaus, Alexander Holthaus, Garrett Holmes, Garett Jones Jun 2019

Adaptive Paddle Board, Alexander Holthaus, Alexander Holthaus, Garrett Holmes, Garett Jones

Mechanical Engineering

This Final Design Review (FDR) document outlines the Adaptive Paddle Board senior project, done by four Mechanical Engineering Students at California Polytechnic State University and provides detail on the project and what the team has accomplished. The goal was to create a universally adaptive paddle board that can be used by the Central California Adaptive Sports Center for a wide range of persons with disabilities. This document highlights current research from patents and existing products, details regarding customer specifications, results from concept generation, the manufacturing and testing that went into the final design, and the process taken to get there. …

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Uav Catapult, Sean Drew Huxley, Benjamin Richard Lacasse, David Matthew Garcia, Jordan Joseph Cearns Jun 2019

Uav Catapult, Sean Drew Huxley, Benjamin Richard Lacasse, David Matthew Garcia, Jordan Joseph Cearns

Mechanical Engineering

This document outlines the Senior Design Project proposed by Dr. Aaron Drake that was assigned to a team of Mechanical Engineering students at California Polytechnic State University, San Luis Obispo. The purpose of this project was to design, build, test, and finalize a launching system for two small, fixed wing, unmanned aerial vehicles (UAVs) owned by Dr. Drake and Cal Poly. The goal was to create a system that was both portable and reliable to use, only requiring a two-person team to use effectively in the field. The most important design requirements were determined to be the launch speed, assembly …

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Retaining Ring Material Wear Analysis And Testing, Thomas Headland, Barten Hansen, Austin Fisher, Kevin Hurtado Jun 2019

Retaining Ring Material Wear Analysis And Testing, Thomas Headland, Barten Hansen, Austin Fisher, Kevin Hurtado

Mechanical Engineering

The chemical mechanical planarization (CMP) of wafers for integrated circuits is an essential – yet expensive – step in their manufacture. CMP machine down-time due to the replacement of process consumables, such as wafer retaining rings, is a significant contributor to the process cost. To reduce the operational cost of their CMP machines, Revasum is interested in exploring new designs and materials for wafer retaining rings to increase their operational lifetime. Background research showed that there is currently no suitable method for testing new retaining ring designs and materials for wear characteristics specific to the CMP process. Available wear testing …

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Burner Design For A Pressurized Oxy-Coal Reactor, William Cody Carpenter Jun 2019

Burner Design For A Pressurized Oxy-Coal Reactor, William Cody Carpenter

Theses and Dissertations

The need for electric power across the globe is ever increasing, as is the need to produce electricity in a sustainable method that does not emit CO2 into the atmosphere. A proposed technology for efficiently capturing CO2 while producing electricity is pressurized oxy-combustion (POC). The objective of this work is to design, build, and demonstrate a burner for a 20 atmosphere oxy-coal combustor. Additionally, working engineering drawings for the main pressure vessel and floor plan drawings for the main pressure vessel, exhaust, and fuel feed systems were produced. The POC reactor enables the development of three key POC technologies: a …

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Me-Em Enewsbrief, June 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Jun 2019

Me-Em Enewsbrief, June 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

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Further Investigation Of Energy And Performance Impacts Of Whole-House Dehumidifier Duct Configurations, Florida Solar Energy Center, Charles Withers, Jr. Jun 2019

Further Investigation Of Energy And Performance Impacts Of Whole-House Dehumidifier Duct Configurations, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

This research project evaluated the energy impacts and dehumidification performance related to how ducted dehumidifiers (DHU) ducts were configured. Lab controlled testing over a variety of weather and latent loads evaluated five-different ducted DHU configurations as follows: Test 1 DHU air ducted from/to the central main body of building. Test 2 DHU air ducted from/to return side of central air conditioner (AC). Test 3 DHU air ducted from/to supply side of AC. Test 4 DHU air ducted from central main body and ducted to supply side of AC. Test 5 DHU air ducted from outdoors and indoors mixed before DHU …

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Fracture Control Modeling With The Finite Element Method, Jorge A. Pluma Reyes Jun 2019

Fracture Control Modeling With The Finite Element Method, Jorge A. Pluma Reyes

Master's Theses

This thesis investigates the feasibility and usability of the finite element method approach in the design of crack arresting devices. Current design and manufacturing practices are improving structures' susceptibility to fracture, in particular brittle fracture; however, cracks in structures are still observed within their lifespans due to severe unexpected service conditions, poor designs, or faulty manufacturing. Crack arrester systems can be added during service to prolong the longevity of structures with sub-critical or critical flaws. Fracture properties of different specific structures under specific services can be obtained experimentally, however, experiments are expensive and of high complexity. Alternatively, the finite element …

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Compact Rake Boundary Layer Data System Module, Nathan Jeffry Hoyt Jun 2019

Compact Rake Boundary Layer Data System Module, Nathan Jeffry Hoyt

Master's Theses

This Thesis describes the design, assembly, programming, and evaluation of the BLDS-M-RAKE, the newest addition to the family of devices called the Boundary Layer Data System (BLDS). The BLDS-M-RAKE is a continuation of the BLDS-M series of devices, a modular approach with updated electronics for boundary layer measurements. The BLDS-M-RAKE records data from a number of sensors, intended to be routed to an array of probes, or rake. Through preliminary testing, a new flexible manifold design from molded silicone and the hardware used on the RFduino development boards from the BLDS-M proof-of-concept modules were validated for use in the final …

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Creating A Learning Environment That Engages Engineering Students In The Classroom Via Communication Strategies, Eleazar Marquez, Samuel Garcia Jun 2019

Creating A Learning Environment That Engages Engineering Students In The Classroom Via Communication Strategies, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this research effort, the authors claim that possessing technical knowledge is not a sufficient asset to establish a learning environment that renders engagement with engineering students during lecture sessions, but rather the integration of various communication strategies that support students’ academic development. Research has noted that classroom context and conditions impact the degree of student learning and engagement and are further enhanced when students feel comfortable communicating with the instructor and with their peers. If such acquaintance is nonexistent, student participation may be stifled and limited despite the technical concerns arising during lecture sessions. Thus, it is imperative for …

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Sand Foot: A Prosthesis For Walking On Sand, Samantha A. Galicinao, John Dewing, Daniel Dugan Dotson, Christopher Urasaki Jun 2019

Sand Foot: A Prosthesis For Walking On Sand, Samantha A. Galicinao, John Dewing, Daniel Dugan Dotson, Christopher Urasaki

Biomedical Engineering

This critical design report describes the product development of a prosthesis for use on sand. Quality of Life Plus (QL+), a national non-profit organization aimed to develop prostheses for veterans and people with disabilities, introduced this project and its accompanying challenger, Sgt. Brady, to Cal Poly’s Interdisciplinary Senior Project class in September 2018. After consulting with Sgt. Brady and QL+ and performing extensive research, the Sand Foot team defined customer requirements and engineering specifications to meet these requirements. Comfortability, durability, and sandproof were key customer requirements. Several conceptual models were brainstormed and a final design was selected based on the …

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Empirical And Theoretical Analysis Of Solar Devices In Public Spaces, Justin Morgan Roberts Jun 2019

Empirical And Theoretical Analysis Of Solar Devices In Public Spaces, Justin Morgan Roberts

Theses and Dissertations

With the debate on global warming and climate change, renewable energy resources, such as solar energy, are being considered. If solar energy is to make a major utility contribution, it will need to be more ubiquitous in today’s society. The research described hereafter analyzes the use of Solar in Public Spaces (SPS). SPS is defined as solar energy used in the public domain to power electronics away from the electric grid. This research specifically examines the viability of integrating solar panels into existing surfaces to charge portable electronics. Viability is evaluated using three criteria: (1) user interaction, (2) technical feasibility, …

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Development Of Heat Transfer Correlations For Low-Reynolds Numbers, Flows In Horizontal Circular Pipes, Latif Eyada Ibraheem Jun 2019

Development Of Heat Transfer Correlations For Low-Reynolds Numbers, Flows In Horizontal Circular Pipes, Latif Eyada Ibraheem

Dissertations

Turbulent flows are intrinsic to most fluid-based engineering systems, including internal combustion engines. In these devices, mixing, scalar transport and heat transfer are both critical for proper operation and challenging to model. In previous work, Kreun et al. [1] modeled a pre-heated intake manifold of a Diesel engine for cold-start simulations. Accurately predicting the heat transfer at the intake port proved to be a challenging task. Existing heat transfer correlations yielded predictions which were (at best) within 20% of the measured values. The discrepancy was attributed to a mismatch between the range of applicability of existing heat transfer models and …

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Epitaxial Growth Of Iii-Nitride Nanostructures And Their Optoelectronic Applications, Moab Rajan Philip May 2019

Epitaxial Growth Of Iii-Nitride Nanostructures And Their Optoelectronic Applications, Moab Rajan Philip

Dissertations

Light-emitting diodes (LEDs) using III-nitride nanowire heterostructures have been intensively studied as promising candidates for future phosphor-free solid-state lighting and full-color displays. Compared to conventional GaN-based planar LEDs, III-nitride nanowire LEDs exhibit numerous advantages including greatly reduced dislocation densities, polarization fields, and quantum-confined Stark effect due to the effective lateral stress relaxation, promising high efficiency full-color LEDs. Beside these advantages, however, several factors have been identified as the limiting factors for further enhancing the nanowire LED quantum efficiency and light output power. Some of the most probable causes have been identified as due to the lack of carrier confinement in …

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Tomato Puree Convective Heat Transfer Simulation Using Boussinesq Approximation, Matteo Fabbri May 2019

Tomato Puree Convective Heat Transfer Simulation Using Boussinesq Approximation, Matteo Fabbri

Theses

With the advance of new technologies, the food industries are requiring systems that allow to produce the desired products with faster rates at cheaper costs. In this case, the study was initiated with the purpose to better understand what happens inside a package containing tomato puree when this is heated above 343 K in a tunnel pasteurizer. If the fluid must reach the thermal and microbiological condition of “pasteurization”, the system must guarantee that the temperature (around 343° Kelvin) is kept for a certain time allowing to pasteurize even the cooler package’s fluid-particle. The faster the system can heat the …

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Mechanics Of Binder-Particle Interactions In Composite Battery Electrodes, Richard Johnson May 2019

Mechanics Of Binder-Particle Interactions In Composite Battery Electrodes, Richard Johnson

Theses

A study into the particle level mechanics of polymer binder and active material used in composite lithium-ion batteries (LIB) has been conducted. Silicon is highly sought after material that can be used as an active material in a composite anode. Its high theoretical capacity can result in batteries that can store more energy than current LIBs, but high volume expansion of Si during charge/discharge cycles leads to rapid capacity fade and poor cyclic life. Understanding the stress that is generated in the binder and the active material due to the volume expansion has not been fully understood. In this study …

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