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Full-Text Articles in Engineering

Publisher Correction: Pore Elimination Mechanisms During 3d Printing Of Metals (Nature Communications, (2019), 10, 1, (3088), 10.1038/S41467-019-10973-9), S. Mohammad H. Hojjatzadeh, Niranjan D. Parab, Wentao Yan, Qilin Guo, Lianghua Xiong, Cang Zhao, Mimglei Qu, Luis I. Escano, Xianghui Xiao, Kamel Fezzaa, Wes Everhart, Tao Sun, Lianyi Chen Dec 2019

Publisher Correction: Pore Elimination Mechanisms During 3d Printing Of Metals (Nature Communications, (2019), 10, 1, (3088), 10.1038/S41467-019-10973-9), S. Mohammad H. Hojjatzadeh, Niranjan D. Parab, Wentao Yan, Qilin Guo, Lianghua Xiong, Cang Zhao, Mimglei Qu, Luis I. Escano, Xianghui Xiao, Kamel Fezzaa, Wes Everhart, Tao Sun, Lianyi Chen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The original version of this Article contained an error in Fig. 4. The x-axis labels in Fig. 4a, b were incorrectly labelled 'Diameter (mm)', rather than the correct 'Diameter (µm)'. This has been corrected in both the PDF and HTML versions of the Article.


Multifunctional Lightweight Aggregate Containing Phase Change Material And Water For Damage Mitigation Of Concrete, Wenyu Liao, Aditya Kumar, Kamal Khayat, Hongyan Ma Dec 2019

Multifunctional Lightweight Aggregate Containing Phase Change Material And Water For Damage Mitigation Of Concrete, Wenyu Liao, Aditya Kumar, Kamal Khayat, Hongyan Ma

Materials Science and Engineering Faculty Research & Creative Works

This paper presents an innovative concept of multifunctional lightweight aggregate, which is produced by loading phase change material (PCM) into the interior of lightweight sand (LWS) and sealing the surface pores using water. The PCM loaded in the LWS functionalizes it as a temperature management agent in concrete, and the water in surface pores enables internal curing. It has been found that the particle shape and pore structure of crushed expanded shale LWS makes it an ideal carrier for PCM, loading sufficient PCM and maintaining better (compared to natural sand) mechanical interlocking. When coupled with the internal curing effect, the …


Grain Refinement In Iron-Based Materials, Simon Naumovich Lekakh, Von Richards, Ronald J. O'Malley, Jun Ge Nov 2019

Grain Refinement In Iron-Based Materials, Simon Naumovich Lekakh, Von Richards, Ronald J. O'Malley, Jun Ge

Materials Science and Engineering Faculty Research & Creative Works

A process for manufacturing an iron-based alloy comprising forming targeted fine oxide and/or carbide dispersoids in a melt, and sequentially precipitating transition-metal nitrides on the dispersoids for heterogeneous nucleation of equiaxed grains. An iron-based cast alloy having a highly equiaxed fine grain structure.


Grain Size Effects In Selective Laser Melted Fe-Co-2v, Wesley Everhart, Joseph William Newkirk Sep 2019

Grain Size Effects In Selective Laser Melted Fe-Co-2v, Wesley Everhart, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

The material science of additive manufacturing (AM) has become a significant topic due to the unique way in which the material and geometry are created simultaneously. Major areas of research within inorganic materials include traditional structural materials, shape memory alloys, amorphous materials, and some new work in intermetallics. The unique thermal profiles created during selective laser melting (SLM) may provide new opportunities for processing intermetallics to improve mechanical and magnetic performance. A parameter set for the production of Fe-Co-2V material with additive manufacturing is developed and efforts are made to compare the traditional wrought alloy to the AM version of …


Effective Elastic Properties Of Additively Manufactured Metallic Lattice Structures: Unit-Cell Modeling, Okanmisope Fashanu, David Murphy, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, Ben Brown, John Porter Aug 2019

Effective Elastic Properties Of Additively Manufactured Metallic Lattice Structures: Unit-Cell Modeling, Okanmisope Fashanu, David Murphy, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, Ben Brown, John Porter

Materials Science and Engineering Faculty Research & Creative Works

Lattice structures are lightweight materials, which exhibit a unique combination of properties such as air and water permeability, energy and acoustic absorption, low thermal conductivity, and electrical insulation. In this work, unit-cell homogenization was used to predict the effective elastic moduli of octet-truss (OT) lattice structures manufactured using selective laser melting (SLM). OT structures were manufactured using a Renishaw AM 250 SLM machine with various relative densities. Compression test was carried out at strain rate 5 x 10-3 m-1 using an MTS frame. Finite element analysis was used in the determination of the OT’s effective elastic properties. Results …


Comparison Of Fatigue Performance Between Additively Manufactured And Wrought 304l Stainless Steel Using A Novel Fatigue Test Setup, M. M. Parvez, Y. Chen, Joseph William Newkirk, Frank W. Liou Aug 2019

Comparison Of Fatigue Performance Between Additively Manufactured And Wrought 304l Stainless Steel Using A Novel Fatigue Test Setup, M. M. Parvez, Y. Chen, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

In this research, a novel adaptive controlled fatigue testing machine was designed for bending type high cycle fatigue test. A unique dual gauge section Krouse type mini specimen was designed for simply supported transverse bending. Displacement controlled fatigue tests were implemented using an electromechanical actuator. The variation in the control signal and load observed during the test provides unique insights into realizing the deterioration of the specimen due to fatigue. These analyses were utilized to compare the fatigue performance of wrought and additively manufactured 304L stainless steel. The influence of the build direction on fatigue performance was also investigated by …


Compressive And Bending Performance Of Selectively Laser Melted Alsi10mg Structures, D. Murphy, O. Fashanu, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, H. Misak, D. Klenosky Aug 2019

Compressive And Bending Performance Of Selectively Laser Melted Alsi10mg Structures, D. Murphy, O. Fashanu, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, H. Misak, D. Klenosky

Materials Science and Engineering Faculty Research & Creative Works

Selective laser melting (SLM) is a widely used additive manufacturing technique that effectively manufactures complex geometries such as cellular structures. However, challenges such as anisotropy and mechanical property variation are commonly found due to process parameters. In a bid to utilize this method for the commercial production of cellular structures, it is important to understand the behavior of a material under different loading conditions. In this work, the behavior of additively manufactured AlSi10Mg under compression, bending, and tension loads was investigated. Vertical and horizontal build directions are compared for each type of loading. Specimens were manufactured using the reduced build …


Elevated Temperature Mechanical And Microstructural Characterization Of Slm Ss304l, G. R. Hecht, Sriram Praneeth Isanaka, Joseph William Newkirk Aug 2019

Elevated Temperature Mechanical And Microstructural Characterization Of Slm Ss304l, G. R. Hecht, Sriram Praneeth Isanaka, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

SLM built SS304L was annealed and water quenched to minimize residual stress and avoid carbide precipitation. Mini-tensile characterization of strength and elongation at temperature conditions up to 800°C, along with observations of the associated microstructural transformations were utilized to understand the changes produced in SLM SS304L. As-built and annealed specimens were found to exhibit decreasing strength and elongation with increasing temperature as expected. Carbide precipitates appeared after short times at high temperatures within both as-built and annealed specimens for all cases, but no brittle intermetallic phase development was observed for any of the temperatures investigated. While the lack of Sigma, …


Infrared Glass–Ceramics With Multidispersion And Gradient Refractive Index Attributes, Laura Sisken, Myungkoo Kang, Johann M. Veras, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Devon Mcclane, Cesar Blanco, Clara Rivero-Baleine, Theresa S. Mayer, Kathleen A. Richardson Aug 2019

Infrared Glass–Ceramics With Multidispersion And Gradient Refractive Index Attributes, Laura Sisken, Myungkoo Kang, Johann M. Veras, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Devon Mcclane, Cesar Blanco, Clara Rivero-Baleine, Theresa S. Mayer, Kathleen A. Richardson

Materials Science and Engineering Faculty Research & Creative Works

Infrared (IR) glass–ceramics (GCs) hold the potential to dramatically expand the range of optical material solutions available for use in bulk and planar optical systems in the IR. Current material solutions are limited to single- or polycrystalline materials and traditional IR-transparent optical glasses. GCs that can be processed with spatial control and extent of induced crystallization present the opportunity to realize an effective refractive index variation, enabling arbitrary gradient refractive index elements with tailored optical function. This work discusses the role of the parent glass composition and morphology on nanocrystal phase formation in a multicomponent chalcogenide glass. Through a two-step …


A Displacement Controlled Fatigue Test Method For Additively Manufactured Materials, Mohammad Masud Parvez, Yitao Chen, Sreekar Karnati, Connor Coward, Joseph William Newkirk, Frank W. Liou Aug 2019

A Displacement Controlled Fatigue Test Method For Additively Manufactured Materials, Mohammad Masud Parvez, Yitao Chen, Sreekar Karnati, Connor Coward, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

A novel adaptive displacement-controlled test setup was developed for fatigue testing on mini specimens. In property characterization of additive manufacturing materials, mini specimens are preferred due to the specimen preparation, and manufacturing cost but mini specimens demonstrate higher fatigue strength than standard specimens due to the lower probability of material defects resulting in fatigue. In this study, a dual gauge section Krouse type mini specimen was designed to conduct fatigue tests on additively manufactured materials. The large surface area of the specimen with a constant stress distribution and increased control volume as the gauge section may capture all different types …


Braze For Ceramic And Ceramic Matrix Composite Components, Sean E. Landwehr, Scott Nelson, Jeremy Lee Watts, Greg Hilmas, William Fahrenholtz, Derek Scott King Jul 2019

Braze For Ceramic And Ceramic Matrix Composite Components, Sean E. Landwehr, Scott Nelson, Jeremy Lee Watts, Greg Hilmas, William Fahrenholtz, Derek Scott King

Materials Science and Engineering Faculty Research & Creative Works

In some examples, a technique may include positioning a first part comprising a ceramic or ceramic matrix composite and a second part comprising a ceramic or a CMC adjacent to each other to define a joint region at the interface of the first part and the second part. In some examples, the joint region may be heated using at least one of a laser or a plasma arc source to heat the joint region to an elevated temperature. The first and second parts may be pressed together and cooled to join the first and second parts at the joint region. …


Methods Of Use And Manufacture Of Silver-Doped, Nano-Porous Hydroxyapatite, Cheol-Woon Kim, Richard K. Brow Jul 2019

Methods Of Use And Manufacture Of Silver-Doped, Nano-Porous Hydroxyapatite, Cheol-Woon Kim, Richard K. Brow

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

A silver-doped, nano-porous hydroxyapatite material is provided that can be utilized to capture radioactive iodine, 129I. Methods of using the silver-doped, nano-porous hydroxyapatite material to remove radioactive iodine, and methods of manufacturing the material are also provided.


Bioprinting With Human Stem Cell-Laden Alginate-Gelatin Bioink And Bioactive Glass For Tissue Engineering, Krishna C. R. Kolan, Julie A. Semon, Bradley Bromet, D. E. Day, Ming-Chuan Leu Jul 2019

Bioprinting With Human Stem Cell-Laden Alginate-Gelatin Bioink And Bioactive Glass For Tissue Engineering, Krishna C. R. Kolan, Julie A. Semon, Bradley Bromet, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Three-dimensional (3D) bioprinting technologies have shown great potential in the fabrication of 3D models for different human tissues. Stem cells are an attractive cell source in tissue engineering as they can be directed by material and environmental cues to differentiate into multiple cell types for tissue repair and regeneration. In this study, we investigate the viability of human adipose-derived mesenchymal stem cells (ASCs) in alginate-gelatin (Alg-Gel) hydrogel bioprinted with or without bioactive glass. Highly angiogenic borate bioactive glass (13-93B3) in 50 wt% is added to polycaprolactone (PCL) to fabricate scaffolds using a solvent-based extrusion 3D bioprinting technique. The fabricated scaffolds …


Effect Of Slm Build Parameters On The Compressive Properties Of 304l Stainless Steel, Okanmisope Fashanu, Mario F. Buchely, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, Heath Misak, Michael Walker Jun 2019

Effect Of Slm Build Parameters On The Compressive Properties Of 304l Stainless Steel, Okanmisope Fashanu, Mario F. Buchely, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, Heath Misak, Michael Walker

Materials Science and Engineering Faculty Research & Creative Works

Selective laser melting (SLM) is well suited for the efficient manufacturing of complex structures because of its manufacturing methodology. The optimized process parameters for each alloy has been a cause for debate in recent years. In this study, the hatch angle and build orientation were investigated. 304L stainless steel samples were manufactured using three hatch angles (0◦, 67◦, and 105◦) in three build orientations (x-, y-, and z-direction) and tested in compression. Analysis of variance and Tukey's test were used to evaluate the obtained results. Results showed that the measured compressive yield strength and plastic flow stress varied when the …


Mechanical Properties Of Heusler Alloys, Wesley Everhart, Joseph William Newkirk May 2019

Mechanical Properties Of Heusler Alloys, Wesley Everhart, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

Heusler alloys have been a significant topic of research due to their unique electronic structure, which exhibits half-metallicity, and a wide variety of properties such as magneto-calorics, thermoelectrics, and magnetic shape memory effects. As the maturity of these materials grows and commercial applications become more near-term, the mechanical properties of these materials become an important factor to both their processing as well as their final use. Very few studies have experimentally investigated mechanical properties, but those that exist are reviewed within the context of their magnetic performance and application space with specific focus on elastic properties, hardness and strength, and …


Modeling And Experimental Determination Of Physical Properties Of Ge X Ga Y Se 1-X-Y Chalcogenide Glasses Ii: Optical And Thermal Properties, Jason Lonergan, Charmayne Lonergan, John Mccloy, Kathleen A. Richardson May 2019

Modeling And Experimental Determination Of Physical Properties Of Ge X Ga Y Se 1-X-Y Chalcogenide Glasses Ii: Optical And Thermal Properties, Jason Lonergan, Charmayne Lonergan, John Mccloy, Kathleen A. Richardson

Materials Science and Engineering Faculty Research & Creative Works

This study systematically analyzed the correlation between topological structure and chemical ordering on the optical and thermal properties of synthesized material in the glass forming region of the GexGaySe1-x-y ternary. A series of ten compositions from 5 to 30 mol% Ge and 5 to 15 mol% Ga were examined within the ternary, showing broadband infrared properties with transmission from 1 to 25 μm. Topological constraint theory applied to compositions examined exhibited sharp inflection at the average coordination number of = 2.67 defined as the chemical threshold where the glass network consists of tetrahedral Ge(Ga)Se2 …


Method And Apparatus For Fabricating Ceramic And Metal Components Via Additive Manufacturing With Uniform Layered Radiation Drying, Ming-Chuan Leu, Amir Ghazanfari, Wenbin Li, Greg Hilmas, Robert G. Landers Apr 2019

Method And Apparatus For Fabricating Ceramic And Metal Components Via Additive Manufacturing With Uniform Layered Radiation Drying, Ming-Chuan Leu, Amir Ghazanfari, Wenbin Li, Greg Hilmas, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A freeform extrusion fabrication process for producing three - dimensional ceramic, metal and functionally gradient composite objects, including the steps of filling a plurality of paste sources with a respective plurality of aqueous paste compositions, operationally connecting respective syringes containing respective aqueous paste compositions to a mix ing chamber, moving a first aqueous paste composition from a first respective paste source into the mixing chamber, moving a second aqueous paste composition from a second respective paste source into the mixing chamber, mixing the first and second aqueous paste compositions to define a first admixture having a first admixture composition, extruding …


Modeling And Experimental Determination Of Physical Properties Of Ge X -Ga Y -Se 1-X-Y Chalcogenide Glasses I: Structure And Mechanical Properties, Jason Lonergan, Charmayne Lonergan, John Mccloy, Kathleen A. Richardson Apr 2019

Modeling And Experimental Determination Of Physical Properties Of Ge X -Ga Y -Se 1-X-Y Chalcogenide Glasses I: Structure And Mechanical Properties, Jason Lonergan, Charmayne Lonergan, John Mccloy, Kathleen A. Richardson

Materials Science and Engineering Faculty Research & Creative Works

A series of ten GexGaySe1-x-y glasses within the topological constraint regime of = 2.3 to 2.8 were processed for physical property testing to compare measured to calculated property values enabling further understanding of structure-related mechanical property evolution. Average bond energies were calculated for each glass to elucidate structure and property relationships. Raman analysis was performed to correlate the topological constraint theory to experimentally determined structural units. Young's modulus and Vickers hardness, respectively, were shown to increase with increasing coordination number from 14.42 GPa and 911 MPa at = 2.4 to 29.44 GPa and 2295 MPa …


Hydration Of Binary Portland Cement Blends Containing Silica Fume: A Decoupling Method To Estimate Degrees Of Hydration And Pozzolanic Reaction, Wenyu Liao, Xiao Sun, Aditya Kumar, Hongfang Sun, Hongyan Ma Apr 2019

Hydration Of Binary Portland Cement Blends Containing Silica Fume: A Decoupling Method To Estimate Degrees Of Hydration And Pozzolanic Reaction, Wenyu Liao, Xiao Sun, Aditya Kumar, Hongfang Sun, Hongyan Ma

Materials Science and Engineering Faculty Research & Creative Works

Determination of degrees of hydration/reaction of components of blended cementitious systems (i. e., cement and SCMs: supplementary cementitious materials) is essential to estimate the systems' properties. Although the best methods for determining degrees of reaction of different SCMs have been recommended by RILEM TC238, they rely on either expensive equipment (e.g., nuclear magnetic resonance) or time-consuming sample preparation and data processing (e.g., backscattered electron image analysis). Furthermore, these methods cannot simultaneously characterize degree of hydration of cement and degree of reaction of SCMs. A novel decoupling method, which can simultaneously estimate the degree of hydration of cement and the degree …


Geometric Effects Of Open Hollow Hydroxyapatite Microspheres Influence Bone Repair And Regeneration In Sprague Dawley Rats, Youqu Shen, M. N. Rahaman, Yongxian Liu, Yue-Wern Huang Apr 2019

Geometric Effects Of Open Hollow Hydroxyapatite Microspheres Influence Bone Repair And Regeneration In Sprague Dawley Rats, Youqu Shen, M. N. Rahaman, Yongxian Liu, Yue-Wern Huang

Materials Science and Engineering Faculty Research & Creative Works

Effective regeneration of bone defects caused by trauma or chronic diseases is a significant clinical challenge. Bone deficiency is overcome using treatments that rely on bone regeneration and augmentation. While various treatments have been investigated with encouraging results, complete and predictable bone reconstruction is often difficult [1]. Synthetic bone grafts have advantages such as consistent quality, safety, and good tissue tolerance. They usually function as inert or osteoconductive implants. Encouraging results from synthetic grafts have been reported. For instance, hollow hydroxyapatite (HA) microspheres showed the ability to facilitate bone repair in rats with non-healing calvarial defects [2,3]. However, new bone …


Characterization Of Mgal₂O₄ Sintered Ceramics, Nina Obradovic, William Fahrenholtz, Suzana Filipovic, Cole Corlett, Pavle Dordevic, Jelena Rogan, Predrag J. Vulic, Vladimir Buljak, Vladimir Pavlovic Apr 2019

Characterization Of Mgal₂O₄ Sintered Ceramics, Nina Obradovic, William Fahrenholtz, Suzana Filipovic, Cole Corlett, Pavle Dordevic, Jelena Rogan, Predrag J. Vulic, Vladimir Buljak, Vladimir Pavlovic

Materials Science and Engineering Faculty Research & Creative Works

Single phase MgAl2O4 was made from a one-to-one molar ratio of MgO and Al2O3 powders mixed using ball-milling. Mixtures of MgO and Al2O3 were subsequently treated in planetary ball mill for 30, 60, 90 and 120 minutes in air. The aim of this study was to examine phase composition, microstructure, and densification behavior of sintered specimens. After sintering in dilatometer at 1500 °C, the powder was converted to single phase MgAl2O4. The results show that mechanical activation improved the densification behavior of MgAl2O4 sintered …


Biodegradable Composite Scaffold For Repairing Defects In Load-Bearing Bones, D. E. Day, Ali Mohammadkhah Mar 2019

Biodegradable Composite Scaffold For Repairing Defects In Load-Bearing Bones, D. E. Day, Ali Mohammadkhah

Materials Science and Engineering Faculty Research & Creative Works

A tissue scaffold for repair and regeneration of bone hard tissue or muscle, skin, or organ soft tissue, including load-bearing bone tissue, the scaffold comprising a core of biocompatible, biodegradable inorganic glass fibers; and a biocompatible, biodegradable, flexible polymer film surrounding the core and adhered to the core.


On The Feasibility Of Tailoring Copper-Nickel Functionally Graded Materials Fabricated Through Laser Metal Deposition, Sreekar Karnati, Yunlu Zhang, Frank W. Liou, Joseph William Newkirk Mar 2019

On The Feasibility Of Tailoring Copper-Nickel Functionally Graded Materials Fabricated Through Laser Metal Deposition, Sreekar Karnati, Yunlu Zhang, Frank W. Liou, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this study, pulse‐width modulation of laser power was identified as a feasible means for varying the chemical gradient in copper—nickel‐graded materials. Graded material deposits of 70 wt. %. copper‐30 wt. %. nickel on 100 wt. %. nickel and vice versa were deposited and characterized. The 70/30 copper—nickel weight ratio in the feedstock powder was achieved through blending elemental copper and 96 wt. %. Ni—Delero‐22 alloy. At the dissimilar material interface over the course of four layers, the duty cycle of power was ramped down from a high value to optimized deposition conditions. This change was theorized to influence the …


Control Upstream Austenite Grain Coarsening During Thin Slab Casting Direct Rolling (Tscdr) Process, Tihe Zhou, Ronald J. O'Malley, Hatem S. Zurob, Mani Subramanian, San-Hyun Cho, Peng Zhang Feb 2019

Control Upstream Austenite Grain Coarsening During Thin Slab Casting Direct Rolling (Tscdr) Process, Tihe Zhou, Ronald J. O'Malley, Hatem S. Zurob, Mani Subramanian, San-Hyun Cho, Peng Zhang

Materials Science and Engineering Faculty Research & Creative Works

Thin-slab cast direct-rolling (TSCDR) has become a major process for flat-rolled production. However, the elimination of slab reheating and limited number of thermomechanical deformation passes leave fewer opportunities for austenite grain refinement, resulting in some large grains persisting in the final microstructure. In order to achieve excellent ductile to brittle transition temperature (DBTT) and drop weight tear test (DWTT) properties in thicker gauge high-strength low-alloy products, it is necessary to control austenite grain coarsening prior to the onset of thermomechanical processing. This contribution proposes a suite of methods to refine the austenite grain from both theoretical and practical perspectives, including: …


Micron-Sized Spinel Crystals In High Level Waste Glass Compositions: Determination Of Crystal Size And Crystal Fraction, C. (Charmayne) E. Lonergan, K. Akinloye-Brown, J. Rice, V. Gervasio, N. Canfield, M. J. Schweiger, J. D. Vienna Feb 2019

Micron-Sized Spinel Crystals In High Level Waste Glass Compositions: Determination Of Crystal Size And Crystal Fraction, C. (Charmayne) E. Lonergan, K. Akinloye-Brown, J. Rice, V. Gervasio, N. Canfield, M. J. Schweiger, J. D. Vienna

Materials Science and Engineering Faculty Research & Creative Works

The compositions utilized for immobilization of high-level nuclear wastes (HLW) are controlled using glass property models to avoid the deleterious effects of crystallization in the high-level waste (HLW) vitrification melters. The type and size of the crystals that precipitate during melter operations (typically at 1150 °C) and idling (∼1000 °C) are significantly impacted by glass composition and thermal history. This study was conducted to measure the impact of melt composition and heat treatment temperature on crystal size and fraction. A matrix of 31 multi-component glasses canvasing the expected Hanford HLW compositional space was developed and the glasses fabricated, and heat …


Melt Property Variation In Gese2-As2se3-Pbse Glass Ceramics For Infrared Gradient Refractive Index (Grin) Applications, Anupama Yadav, Andrew Buff, Myungkoo Kang, Laura Sisken, Charmayne Smith (Lonergan), Jason Lonergan, Cesar Blanco, Michael Antia, Megan Driggers, Andrew Kirk, Clara Rivero-Baleine, Theresa Mayer, Andrew Swisher, Alexej Pogrebnyakov, A. R. Hilton, Greg Whaley Jan 2019

Melt Property Variation In Gese2-As2se3-Pbse Glass Ceramics For Infrared Gradient Refractive Index (Grin) Applications, Anupama Yadav, Andrew Buff, Myungkoo Kang, Laura Sisken, Charmayne Smith (Lonergan), Jason Lonergan, Cesar Blanco, Michael Antia, Megan Driggers, Andrew Kirk, Clara Rivero-Baleine, Theresa Mayer, Andrew Swisher, Alexej Pogrebnyakov, A. R. Hilton, Greg Whaley

Materials Science and Engineering Faculty Research & Creative Works

Melt size-dependent physical property variation is examined in a multicomponent GeSe2-As2Se3-PbSe chalcogenide glass developed for gradient refractive index applications. The impact of melting conditions on small (40 g) prototype laboratory-scale melts extended to commercially relevant melt sizes (1.325 kg) have been studied and the role of thermal history variation on physical and optical property evolution in parent glass, the glass' crystallization behavior and post heat-treated glass ceramics, is quantified. As-melted glass morphology, optical homogeneity and heat treatment-induced microstructure following a fixed, two-step nucleation and growth protocol exhibit marked variation with melt size. These attributes …


Near-Field Electrospinning Of A Polymer/Bioactive Glass Composite To Fabricate 3d Biomimetic Structures, Krishna C. R. Kolan, Jie Li, Sonya Roberts, Julie A. Semon, Jonghyun Park, D. E. Day, Ming-Chuan Leu Jan 2019

Near-Field Electrospinning Of A Polymer/Bioactive Glass Composite To Fabricate 3d Biomimetic Structures, Krishna C. R. Kolan, Jie Li, Sonya Roberts, Julie A. Semon, Jonghyun Park, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Bioactive glasses have recently gained attention in tissue engineering and three-dimensional (3D) bioprinting because of their ability to enhance angiogenesis. Some challenges for developing biological tissues with bioactive glasses include incorporation of glass particles and achieving a 3D architecture mimicking natural tissues. In this study, we investigate the fabrication of scaffolds with a polymer/bioactive glass composite using near-field electrospinning (NFES). An overall controlled 3D scaffold with pores, containing random fibers, is created and aimed to provide superior cell proliferation. Highly angiogenic borate bioactive glass (13-93B3) in 20 wt.% is added to polycaprolactone (PCL) to fabricate scaffolds using the NFES technique. …