Engineering Commons^™

Prediction Of Isotropic Strain Hardening Material Properties Using Gradient Boosted Regression Tree Method And Hyperparameter Optimization, Darren R. Promer

Masters Theses

In this study a new technique is proposed for the determination of elastic-plastic stress-strain relations for isotropic materials using the force-displacement output from an instrumented indentation test, finite element simulation, and machine learning methods. This non-destructive testing methodology has promising potential for industry implementation. Applications to benefit from this method include the characterization of localized material properties on surface engineered components, and the post-manufacturing assessment of material properties for items such as additively manufactured metallic components and load-bearing welded joints.

Currently, the capability of the instrumented indentation test for determining material properties is limited to the elastic modulus and surface …

A Multiscale Thermomechanical Metal Additive Manufacturing Simulation And The Impact Of Geometry On Residual Stress And Distortion, Luis Fernando Silva Velasco

Masters Theses

Metal additive manufacturing is an enabling technology for the rapid prototyping and manufacturing of geometrically complex parts that would otherwise be difficult or impossible to manufacture. However, the manufacturing process can produce undesired residual stresses and distortions. The first part of the work describes the implementation of a multiscale, thermo-mechanical simulation modeling the metal powder bed fusion additive manufacturing process. NASA’s Micromechanics Analysis Code was is to incorporate the microscale effects of an evolving material porosity on the predicted macroscale residual fields. The simulation shows that modeling an evolving material porosity, as the material transitions from a metal powder to …

Cellulose Based Separator For High-Performance Lithium-Ion Batteries, Akshit Vaidya

Masters Theses

During the past two decades, lithium-ion batteries (LIBs) have gained great success in the field of portable devices, and currently, are penetrating to the market of vehicles. Compared to the fast development of LIBs, little efforts have been dedicated to the separator, which is one of the most important components of LIBs. Primarily, the lithium-ion battery separator has two functions, one is to prevent direct contact between the positive and negative electrodes, and the other is to provide a path for effective ionic transportation. Currently, the separator market of LIBs is dominated by polyolefin materials such as polypropylene, polyethylene, and …

The Modification Of A Curtain Coating Formulation: A Study Of Rheology And Surface Tension, And Their Effect On Pitting, Samantha Leigh Schoenfelder

Masters Theses

When an undisclosed recycled fiber mill installed a “two-slotted” curtain coater to replace their air knife coater, a prominent defect arose known as “pitting,” which is also called pinholing or cratering. Pitting occurs when the coating of the sheet has small holes that mar its surface, which, when clustered together or larger in size, can cause print breakup during the printing process.

Through research, pitting is known to be caused by a boundary layer of air that gets laterally pulled in between the coating and board during their initial contact. Thus, rheological properties and the surface tension of the curtain …

Development Of An Effective Portable And Flexible Glove For Hand Tremor Suppression, Abdulrahem Turkistani

Masters Theses

This paper presents the work carried out in designing and developing a prototype for a tremor suppression system that reduces hand tremor by counteracting vibrations initiated from a patient’s shaking hand. This system includes a glove with a built-in vibration simulation module that oscillates and mimics the hand vibration. The oscillation is generated by a DC motor mounted on the top of the glove, and can vary in degree of vibration. The glove is also equipped with an accelerometer-gyroscope based micro-electromechanical system (MEMS) and vibrating coin motors mounted on each finger, both interfaced with a microcontroller. The microcontroller used in …

Minimization Of Metamerism In Wood Grain Printing Using Different Gcr Settings, Vinay Anil Turke

Masters Theses

In printing industry, prototyping is necessary to ensure quality reproduction of jobs. Conventional printing processes like gravure cannot be used for prototyping because of high manufacturing cost of gravure cylinders. Such challenges can be successfully tackled by use of relatively cheap and flexible printing processes, such as inkjet. Even though inkjet printing is a cost effective way for prototyping, it has its own limitations, especially in the case of woodgrain printing. Wood-grain patterns need to be printed with a release coating and adhesive. Inkjet printers are incapable of printing release coating and adhesive because release coat and adhesive require certain …

Oxidized Phospholipids Regulation Of The Monocyte Recruitment Parthway In Human Aortic Endothelial Cells, Piao Jian Tan

Masters Theses

Low-density lipoprotein particles in blood plasma invade the endothelium and become oxidized, creating risk of CHD associated with atherosclerosis, the main underlying condition in coronary heart disease. Oxidation products of the phospholipid 1-palmitoyl- 2-arachidonoyl-sn-glycerol-3-phosphatidylcholine (PAPC) are bioactive components of minimally oxidized LDL that stimulate endothelial cells that line the artery, leading to monocyte binding and atherosclerosis. It is hypothesized that the regulation of the monocyte recruitment pathway by these oxidized phospholipids is mediated by the binding of OxPAPC to one or more mediating proteins. Human recombinant VEGFR2, GRP78, and EP2bind to OxPNB, a biotinylated analog of OxPAPC, demonstrated using Western …

Self-Supported Printed Multi-Layer Capacitors, Michael James Joyce

Masters Theses

The increasing demand for miniaturized electronic devices has increased the need for rechargeable micro-power sources. Although lithium and lithium ion batteries have been utilized in these applications since the late 1990s, other energy harvesting technologies, such as thermal, mechanical, and solar, are now being used to augment batteries to enable systems to be self-powered. However, the lifetime of any battery is finite, which may be a major problem when the application is in a permanent structure or medical implant device. For power or significant energy storage applications, printed multilayer capacitors or supercapacitors are being explored as an enhancement, or replacement …

Electroplating Of Nanoengineered Polymer Substrate, Brandon Voelker

Masters Theses

The development of a polyethylene based polymer with metallic inclusions, a nanoengineered polymer, has recently opened up great potential for many new commercial and industrial applications. The major advantage of developing these nanoengineered polymers is to be able to tailor the resistance and other properties by varying the composition of the polymer. The industrial usage of this polymer benefits from the addition of an electrically conductive, metallic coating. This research develops methods of electroplating nickel and copper layers on to the polymer substrates using DC and pulsed techniques.

Electroplating is conducted in a 1000 mL beaker using a specialized plating …

A Novel Silica-Based Nano Pigment As A Titanium Dioxide Replacement, Ryan Stoneburner

Masters Theses

This research focused on the evaluation of a new Silica-based pigment for the replacement of titanium dioxide (TiO₂) in paperboard coatings. The silica-based pigment has shown the ability to be a replacement in terms of functionality and runnability. TiO₂ is currently the highest opacifying pigment used in paper coatings, but it is also the most costly. Finding a less expensive pigment that doesn't reduce effectiveness is critical to reducing the cost of TiO₂ formulations. To evaluate the new pigment, coatings will be applied using a Cylindrical Laboratory Coater (CLC) with varying amounts of TiO₂ and …

Use Of Polymer Rapid Tools As Functional Injection Mold Tooling, Sean Derrick

Masters Theses

Conventional tool making for injection molded plastics is expensive, time consuming, and generates a great deal of waste. Presently, industry is waiting for what is commonly referred to as Rapid Tooling (RT). The greatest opportunity for RT implementation would be the use of Additively Manufacturing (AM) technology. Specifically, AM techniques which use a high strength polymer resin substrate.

The following research is an initial feasibility study to determine if Polymer Rapid Tools (PRTs) could be used as functional injection mold tooling. The objective of the research was to determine if a PRT could mold a variety of features to a …

Improved Deinkability Of Lep (Liquid Electrophotography) Digital Prints, Zheng Wei

Masters Theses

Digital printing plays a very important role in the life of modern society. With the development of digital printing technologies, and the increasing market share of digital printing, the amount of digital prints in waste paper is rapidly increasing. Under “green” manufacturing and environmental sustainability, deinking of digital print inks is an urgent problem that needs to be solved. Indigo is a typical series of HP (Hewlett-Packard) digital presses that use a liquid ink named ElectroInk (Liquid Electrophotography or LEP). The particle size of HP ElectroInk is very small, 1-2 microns, which is smaller than dry toners. But, during flotation, …

Development Of Knowledge Base Of Concrete Bridge Maintenance System, Bahre Karam

Masters Theses

Bridges are the key elements of any transportation system of a country. Bridges are expensive structures and therefore, it's essential to maintain and repair them on regular basis. Almost one third of the bridges in United States are reported to be in some what deteriorated conditions. This Research presents the development of knowledge base for decision support system for concrete bridges.

During this research various concrete bridge problems are investigated including COlTosion, delamination, cracks, spalling and scour etc. The inspection tools and techniques are addressed in order to identify these problems both for above and below water surface. The various …

Microwave Pretreatment Of Corn Stover For Anaerobic Digestion, Abhishek D. Saxena

Masters Theses

Anaerobic digestion is one of the several technologies used for biomass conversion to electricity or heat. This thesis focused on microwave irradiation of corn stover as a pretreatment for anaerobic digestion, and studies its impact on methane production.

The first run comprised three sets of stover soaked overnight in water, dilute sulfuric acid and dilute acetic acid, and each treated to three different levels of microwave irradiation. The results indicated a high variability in the data of the water set, which showed that there was no clear impact of microwave pretreatment on methane production. The dilute sulfuric acid and dilute …

The Effect Of Non-Stoichiometry On The Structure Of La-Ni And La-Ni-Ga Alloys, Pertrice Auguste Wethey

Masters Theses

Non-stoichiometric samples of the AB₅ system defined by the formula La_1-yNi_5+2y and LaNi_5+2xGa_1-x were cast using an arc-melting furnace. The samples were then analyzed to determine their lattice parameters and phases present using XRD. They were then heat-treated to produce homogeneous compounds and quenched with the intention of retaining high temperature compositions. Following the heat-treatment, the alloys underwent XRD again as well as SEM/EDS. The XRD information was analyzed using Rietveld refinement and the elemental data derived from the EDS was used to ascertain the compositions were statistically akin to the weighed values. …

Investigation Of Electrical Properties And Structure Of Vacuum Evaporated C60 Films, Angiras D. Pandya

Masters Theses

C₆₀ is an important electronic material and its properties can be tuned by thermal annealing process and solid phase crystallization process. These properties were investigated as a function of thermal annealing temperature and solid phase crystallization. However there is no systematical study on annealing effect and Solid Phase Crystallization of C₆₀ films. In this study, the effect of thermal annealing on formation of nanocrystalline C₆₀ thin films were investigated for annealed samples and solid phase crystallized samples. The C₆₀ films described here were prepared by vacuum thermal evaporation method. The structural properties of C₆₀ films …

Hot Melt Inks For Rotogravure-Formulation, Printability And Rheology, Hrishikesh Shreeram Bhide

Masters Theses

A new generation of "Hot melt inks for Rotogravure" was formulated. They melt during heating and reach printable viscosity between 75° C and 130° C, depending on formulation. After printing onto substrate, they solidify. Selections of the best formulations were done based on ink rheology, and print analysis. The formulated inks were also printed on the Moser sheet-fed proofing press .. The rheological data indicated that hot melt inks (without viscosity modifier) have viscosity in the range of 10°-10¹ Poise at 95°C. After printed on a laboratory gravure K-Proofer, the inks showed good reflective density (0.90 - Yellow, 1.30 …

Effect Of Modified Clay-Zeolite Pigment On The Viscoelastic, Optical, And Printing Properties Of A Lwc Gravure Coating, Lokendra Pal

Masters Theses

This study investigates the influence of modified clay- zeolite pigment on the viscoelastic, optical, and printing properties of a LWC coating. Currently, lightweight, coated papers have experienced problems with mottle, distortion, fiber puffing and poor print quality when printed with water-based inks. However, water-based inks represent a proven solution to reducing volatile organic compound (VOCs) emissions. Poor wetting and ink spreading on the paper surface constitute the majority of print quality issues associated with the water-based printing of LWC papers.

Similar problems are encountered during the printing of ink jet papers due to high percentage of water contained in these …

Development Of Water-Based Ink System For Braille Printing, Saurabh Varma

Masters Theses

The most commonly used system of writing by and for blind persons is called Braille, named after its French inventor, Louis Braille (1809-1952). Braille is comprised of a rectangular six-dot cell on its end, with up to 63 possible combinations using one or more of the six dots. Braille is the only reliable method of literacy for blind persons, because it enables them to read and write by touch¹.

Currently, Braille is printed by special embossers that serve as a printing press. These embossers create Braille output when it is attached appropriately to computers. The speed of these …

Metastable Phases Of Mgo-Tio2 Solid Solutions, Liang-Chieh Ma

Masters Theses

Magnesium titanium oxide powders were synthesized by the sol-gel method using alkoxides of magnesium and titanium with different ratios. Matastable phases of qandilite, Mg₂TiO₄, were found with Mg:Ti ratios down to 1.52:1 in lower temperature 600 °C than in the equilibrium condition which is above 1200 °C. Powder samples were examined by neutron powder diffraction and X-ray photoelectron spectroscopy (XPS) for analysis of structure and oxidation states. Also, samples were tested for the Mg:Ti ratios by induced coupled plasma atomic emission spectrometry. The structure refinements of the samples were done by General Structure Analysis System (GSAS) …

Lateral Migration Of A Solid Particle In Shear Flow, Wutthapong Jiraporncharoen

Masters Theses

Lateral migration of solid particles in shear flow is observed in various industrial applications. Suspensions in a blade coater, a device used to apply coating pigment to a base paper to improve paper properties, is an example. Particle hydrodynamics will affect the quality of coated paper and runnability of the coater especially when the speed of the coating machine is very high or the pigment concentration is increased.

Many factors will affect the particle migration. The wall repulsion or lubrication effect forces the particle away from a wall to the channel center. The inertial effects are increased by increasing the …

An Analysis Of Texture Resulting From Thermomechanical Processing Of Ti-6al-V, David J. Brock

Masters Theses

An investigation of texture and microstructure formation in Ti-6Al-4V after thermomechanical processing and heat treating was performed. X-ray diffraction was used to measure prismatic and pyramidal pole figures. These pole figures were used to calculate basal pole figures, which showed significant changes in texture from heavy rolling and near or above β-transus heat treatments. Primary texture components were found to be strengthened by near β-transus heat treatments. For heavily rolled material, above β-transus heat treatments were found to reverse the primary texture components order of dominants. Heavy rolling was found to reduce the RD component and strengthen the TD.

Effect Of Poly Acrylate Addition On Coating Color Rheology, Water Retention And Coating Performance, Shambhu Nath

Masters Theses

Five polyacrylate samples were used to study their effects on coating color rheology, water holding and runnability. The Cylindrical Laboratory Coater was used to apply the coatings and study the runnability of the coating colors. The healing tendencies of the coatings were studied by inducing a scratch under the blade. The higher acid level and degree of crosslinking of the polyacrylate gave higher viscosity and the higher acid level also gave higher water retention. Coating colors containing polyacrylates were less prone to dilatancy at high shear. The addition of polyacrylate reduced the healing of coating colors, but for the same …

Silicon Carbide/Electroless Nickel Composite Plating For Aluminum Substrates, Ben Charbit

Masters Theses

The effectiveness of producing a composite coating by suspending micron-sized particles in an electroless nickel bath while plating a 2024T4 aluminum alloy part was studied. The variation in the count of particles trapped in the nickel coating due to changes in the particle size, concentration of the particles in the bath, and the substrate surface texture was also studied. Particle sizes of 1 micron and 10 microns, concentrations of 15 gr/lt and 30 gr/lt, and polished and blasted textures were used. It was found that this technique is an effective way to produce composite coatings rendering a high number of …

Prediction Of Paper Color: A Process Simulation Approach, Mayank Chaturvedi

Masters Theses

A simulation model was developed for a dye mixing process and for the prediction of the optical properties of the paper. The model was integrated with the MAPPS (Modular Analysis of Pulp and Paper Systems) simulation software package. The model was validated using dyed handsheets made in a laboratory and dyed paper made on a pilot papermachine. Validation comprised of prediction of the optical properties of the handsheets and the machine-made paper which contained various combinations of three non-fluorescent dyes. Sheet reflectances were predicted at 20 nanometer intervals for discrete light wavelength range of 400 to 700 nanometers and verified …

Optimization Of Sodium Carbonate-Sodium Hydroxide Pulping Of Wheat Straw For Corrugating Medium Production, Irmak Yayin

Masters Theses

This study's primary objective was to present sodium carbonate pulping as an alternative to soda or lime pulping of wheat straw for corrugating medium production. If sodium carbonate pulping is comparable with soda pulping in terms of strength properties, it could be the preference of choice because the recovery of sodium carbonate is simpler requiring less capital investment. The two strength properties that were optimized with respect to total chemical charge, cooking time, and sodium hydroxide fraction in the cooking liquor were Concora crush resistance and STFI compressive strength. These are the two most important strength properties for the end …

An Experimental Investigation Of Bevelled Blade Coating For Paper, Mustafa Naci Altug

Masters Theses

In this study the total dynamic force (TDF) acting on the blade was determined at three different web speeds. The objective was to compare quantitatively the experimental results with the predictions of existing models to show whether or not any of these models predict coat weight development. The existing models include the lubrication theory, impact model, lateral force, and combinations of these models.

Under the conditions investigated, the estimated TDF was in good agreement only with the impact force (sum of impulse and hydrodynamic forces) model of blade coating. The impulse force accounted for 94% of the TDF and, therefore, …

The Relationship Of Pore Volume And Pore Size Distribution To The Development Of Gloss And Scattering Coefficient, John A. Cook

Masters Theses

This study describes in a quantitative manner the relationships between coating structure and optical properties. Gloss, scattering coefficient and void volume were measured after applying different blends of polystyrene spheres to mylar film. Each coating was modeled using large spherical particles of the same size ratios to measure pore size distribution. The coating structure followed well with theoretical packing characteristics of spheres. Optical properties were related to changes in coating structure. Scattering coefficient and gloss correlated better with pore size distribution than particle size. Gloss increased when total void volume was reduced, while the scattering coefficient decreased.

A Dynamic Study Of The Effect Of Cationic Starch Molecular Weight And Charge On Filler And Fines Flocculation, Deflocculation, And Reflocculation, Bob Shian-Hou Ching

Masters Theses

A modified laboratory instrument was used to dynamically monitor the flocculation of fines and filler under various shear conditions on the "seconds" basis. A three-way factorial design and ANOVA were used to evaluate the significance of cationio starch molecular weight and charge in affecting fines and filler flocculation, deflocculation, and reflocculation. The reduction of molecular weight under high shear was suggested by the results. Both main effects and interaction effects of charge and molecular weight were important in determining flocculation. Charge was the only significant factor for the reflocculation process. Molecular weight was more important than charge in imparting shear …

Isolation And Characterization Of The Dimers Formed In The Free-Radical And Anionic Initiated Polymerization Of Alpha-Methylstryene, Kevin S. Bosman

Masters Theses

No abstract provided.