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2019

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Materials Science and Engineering

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Articles 1 - 30 of 202

Full-Text Articles in Engineering

Cdse Quantum Dots Synthesis Laboratory Course For High School Students, Danlin Zuo, Gyuseok Kim, David Jones Dec 2019

Cdse Quantum Dots Synthesis Laboratory Course For High School Students, Danlin Zuo, Gyuseok Kim, David Jones

Protocols and Reports

Cadmium selenide quantum dot is a fascinating subject for leading high school students to the quantum world. An 8-hour laboratory course for up to 12 high school students is proposed. The 8-hour course consist of two 4-hours sections. This laboratory course includes the quantum dot syntheses, absorption and emission characterization, and data analysis. The proposes process runs at relatively lower temperature which means safe and easy, and shows apparent experimental results.


Characterization Of Zirconium Oxides Part I: Raman Mapping And Spectral Feature Analysis, Corey M. Efaw, Jordan L. Vandegrift, Michael Reynolds, Samuel Mcmurdie, Brian J. Jaques, Hui Xiong, Michael F. Hurley Dec 2019

Characterization Of Zirconium Oxides Part I: Raman Mapping And Spectral Feature Analysis, Corey M. Efaw, Jordan L. Vandegrift, Michael Reynolds, Samuel Mcmurdie, Brian J. Jaques, Hui Xiong, Michael F. Hurley

Materials Science and Engineering Faculty Publications and Presentations

Raman mapping of sectioned zirconium cladding oxides was performed to analyze different spectral features before and after breakaway, as well as between zirconium and its alloys Zr-2.65Nb, Zry-3, and Zry-4. Oxide phase composition, or percent tetragonality, was defined to compare tetragonal to monoclinic zirconia. Percent tetragonality was spatially mapped to support distinction of zirconia phase distribution. A tetragonal-rich layer was seen at the metal/oxide interface, while post-breakaway samples exhibited increased amount of tetragonal phase in the bulk of their oxides. Spatial mapping of spectral peak location and half-width at half-maximum was accomplished to distinguish differences in stability mechanisms ...


Effect Of Annealing On The Contact Resistance Of Aluminum On A P-Type Substrate, Shrey Shah, George Patrick Watson Nov 2019

Effect Of Annealing On The Contact Resistance Of Aluminum On A P-Type Substrate, Shrey Shah, George Patrick Watson

Protocols and Reports

Aluminum contacts are widely used to form both ohmic and rectifying contacts. The process to form these contacts involves annealing, thus it is important to study the effect of annealing on the electrical properties of the contacts. Here, we present a way to measure the contact resistance of aluminum contacts formed on a p-type silicon substrate. It was found the contact resistivity decreased by an average of 18%. It was thus found that annealing at 400°C in a forming gas environment improves the electrical properties of aluminum contacts.


Why The Crackling Deformations Of Single Crystals, Metallic Glasses, Rock, Granular Materials, And The Earth’S Crust Are So Surprisingly Similar, Karin A. Dahmen, Jonathan T. Uhl, Wendelin J. Wright Nov 2019

Why The Crackling Deformations Of Single Crystals, Metallic Glasses, Rock, Granular Materials, And The Earth’S Crust Are So Surprisingly Similar, Karin A. Dahmen, Jonathan T. Uhl, Wendelin J. Wright

Faculty Journal Articles

Recent experiments show that the deformation properties of a wide range of solid materials are surprisingly similar. When slowly pushed, they deform via intermittent slips, similar to earthquakes. The statistics of these slips agree across vastly different structures and scales. A simple analytical model explains why this is the case. The model also predicts which statistical quantities are independent of the microscopic details (i.e., they are "universal"), and which ones are not. The model provides physical intuition for the deformation mechanism and new ways to organize experimental data. It also shows how to transfer results from one scale to ...


A Parametric Study For In-Pile Use Of The Thermal Conductivity Needle Probe Using A Transient, Multilayered Analytical Model, Courtney Hollar, Austin Fleming, Kurt Davis, Ralph Budwig, Colby Jensen, David Estrada Nov 2019

A Parametric Study For In-Pile Use Of The Thermal Conductivity Needle Probe Using A Transient, Multilayered Analytical Model, Courtney Hollar, Austin Fleming, Kurt Davis, Ralph Budwig, Colby Jensen, David Estrada

Materials Science and Engineering Faculty Publications and Presentations

By utilizing an in-pile measurement, thermal conductivity can be determined under prototypic conditions over a range of burnup. In this work we develop a multilayer quadrupoles analytical model to describe the transient thermal interactions between a line heat source (i.e. needle probe) and cylindrical nuclear fuel geometry for inpile thermal conductivity measurements. A finite element analysis of the detailed needle probe geometry was compared to results from the analytical model to verify the assumptions made in the analytical model. Experimentally, the needle probe was used to measure the thermal properties of polytetrafluoroethylene (PTFE) and stainless steel 304 with three ...


From Critical Behavior To Catastrophic Runaways: Comparing Sheared Granular Materials With Bulk Metallic Glasses, Alan A. Long, Dmitry Denisov, Peter Schall, Todd C. Hufnagel, Xiaojun Gu, Wendelin J. Wright, Karin A. Dahmen Nov 2019

From Critical Behavior To Catastrophic Runaways: Comparing Sheared Granular Materials With Bulk Metallic Glasses, Alan A. Long, Dmitry Denisov, Peter Schall, Todd C. Hufnagel, Xiaojun Gu, Wendelin J. Wright, Karin A. Dahmen

Faculty Journal Articles

The flow of granular materials and metallic glasses is governed by strongly correlated, avalanche-like deformation. Recent comparisons focused on the scaling regimes of the small avalanches, where strong similarities were found in the two systems. Here, we investigate the regime of large avalanches by computing the temporal profile or “shape” of each one, i.e., the time derivative of the stress-time series during each avalanche. We then compare the experimental statistics and dynamics of these shapes in granular media and bulk metallic glasses. We complement the experiments with a mean-field model that predicts a critical size beyond which avalanches turn ...


Proppant For Use In Hydraulic Fracturing To Stimulate A Well, Thomas Lee Robl, Anne Elizabeth Oberlink Oct 2019

Proppant For Use In Hydraulic Fracturing To Stimulate A Well, Thomas Lee Robl, Anne Elizabeth Oberlink

Center for Applied Energy Research Faculty Patents

A proppant for use in hydraulic fracturing to stimulate a well is provided. The proppant is fly ash particles having a mean particle size (d50) of between 45 μm and 150 μm and a size distribution defined by (d10) ≤ 5 μm and (d98) ≤ 250 μm.


Correction Of Pattern Size Deviations In The Fabrication Of Photomasks Made With A Laser Direct-Writer, Ningzhi Xie, George Patrick Watson Oct 2019

Correction Of Pattern Size Deviations In The Fabrication Of Photomasks Made With A Laser Direct-Writer, Ningzhi Xie, George Patrick Watson

Protocols and Reports

When using Heidelberg DWL66+ laser writer to fabricate the photomask, the pattern feature dimensions may have deviations. These deviations can be caused by the lithography process and the undercut in the metal etch process. The same deviation value of 0.8µm was found to appear in all the patterns independent of the pattern original size and local pattern density. To overcome this universal deviation, a universal bias is suggested to be applied to the original patterns during the data preparation for the lithography process. In order to ensure this pre-exposure bias method can work, both the laser direct-write exposure conditions ...


Determining Surface Energy Of Porous Substrates By Spray Ionization, Deidre E. Damon, Yosef S. Maher, Danyelle M. Allen, Jill Baker, Boyce Chang, Simon Maher, Martin M. Thuo, Abraham K. Badu-Tawiah Oct 2019

Determining Surface Energy Of Porous Substrates By Spray Ionization, Deidre E. Damon, Yosef S. Maher, Danyelle M. Allen, Jill Baker, Boyce Chang, Simon Maher, Martin M. Thuo, Abraham K. Badu-Tawiah

Materials Science and Engineering Publications

We have developed a new spray-based method for characterizing surface energies of planar, porous substrates. Distinct spray modes (electrospray versus electrostatic-spray), from the porous substrates, occur in the presence of an applied DC potential after wetting with solvents of different surface tension. The ion current resulting from the spray process maximizes when the surface energy of the porous substrate approaches the surface tension of the wetting solvent. By monitoring selected ion current (e.g., benzoylecgonine, m/z 290→168) with a mass spectrometer or total ion current with an ammeter, the solvent surface tension yielding the maximum ion current was ...


In Situ Tem Study Of The Amorphous-To-Crystalline Transition During Dielectric Breakdown In Tio2 Film, Xinchun Tian, Chloe Cook, Wei Hong, Tao Ma, Geoff L. Brennecka, Xiaoli Tan Oct 2019

In Situ Tem Study Of The Amorphous-To-Crystalline Transition During Dielectric Breakdown In Tio2 Film, Xinchun Tian, Chloe Cook, Wei Hong, Tao Ma, Geoff L. Brennecka, Xiaoli Tan

Materials Science and Engineering Publications

Dielectric breakdown of oxides is a main limiting factor for improvement of the performance of electronic devices. Present understanding suggests that defects produced by intense voltage accumulate in the oxide to form a percolation path connecting the two electrodes and trigger the dielectric breakdown. However, reports on directly visualizing the process at nanoscale are very limited. Here, we apply in situ transmission electron microscopy to characterize the structural and compositional changes of amorphous TiO2 under extreme electric field (~100 kV/mm) in a Si/TiO2/W system. Upon applying voltage pulses, the amorphous TiO2 gradually transformed to crystalline sub-stoichiometric rutile ...


Soil-Recycled Aggregate-Geopolymer Road Base/Subbase Mixtures: Steps Towards Sustainability, Mohammad Khattak, Daniel Odion Oct 2019

Soil-Recycled Aggregate-Geopolymer Road Base/Subbase Mixtures: Steps Towards Sustainability, Mohammad Khattak, Daniel Odion

Publications

This study deals with the development of Soil-Geopolymer mixtures using flyash, alkali activator and recycled aggregates (RAG) including recycled concrete (RCA) and reclaimed asphalt (RAP) as an alternative to soil-cement for pavement base and subbase layers. Several mix constituents were varied such as flyash type and content, RCA and RAP content and ratio of sodium silicate and sodium hydroxide. Experiment design was established and mechanical and durability characteristics of Soil-RAG-Geopolymer mixtures were evaluated and then compared to the conventional soil-cement mixtures. The results of the testing showed that for the selected Soil-RAG-Geopolymer mixtures the strength, stiffness, permanent deformation, and durability ...


Reduction Of Structural Damage From The Thermal Expansion Of Concrete Using Multifunctional Materials, Darren Hartl, Mirmilad Mirsayar Oct 2019

Reduction Of Structural Damage From The Thermal Expansion Of Concrete Using Multifunctional Materials, Darren Hartl, Mirmilad Mirsayar

Data

Corresponding data set for Tran-SET Project No. 18STTAM01. Abstract of the final report is stated below for reference:

"This study leveraged past successes in the analysis and design of shape memory alloy (SMA) components to address the issue of thermal expansion in concrete structures. Since the SMA used in the current work is relatively cheaper than other common SMAs (less than $50/lb compared to NiTi which is $200/lb due to difficulties in processing), it is anticipated that the findings of the study could be implemented in real infrastructures made of concrete, asphalt concrete, and other complex large infrastructure ...


Soil-Recycled Aggregate-Geopolymer Road Base/Subbase Mixtures: Steps Towards Sustainability, Mohammad Khattak, Daniel Odion Oct 2019

Soil-Recycled Aggregate-Geopolymer Road Base/Subbase Mixtures: Steps Towards Sustainability, Mohammad Khattak, Daniel Odion

Data

Corresponding data set for Tran-SET Project No. 18GTLSU10. Abstract of the final report is stated below for reference:

"This study deals with the development of Soil-Geopolymer mixtures using flyash, alkali activator and recycled aggregates (RAG) including recycled concrete (RCA) and reclaimed asphalt (RAP) as an alternative to soil-cement for pavement base and subbase layers. Several mix constituents were varied such as flyash type and content, RCA and RAP content and ratio of sodium silicate and sodium hydroxide. Experiment design was established and mechanical and durability characteristics of Soil-RAG-Geopolymer mixtures were evaluated and then compared to the conventional soil-cement mixtures. The ...


Reduction Of Structural Damage From The Thermal Expansion Of Concrete Using Multifunctional Materials, Darren Hartl, Mirmilad Mirsayar Oct 2019

Reduction Of Structural Damage From The Thermal Expansion Of Concrete Using Multifunctional Materials, Darren Hartl, Mirmilad Mirsayar

Publications

This study leveraged past successes in the analysis and design of shape memory alloy (SMA) components to address the issue of thermal expansion in concrete structures. Since the SMA used in the current work is relatively cheaper than other common SMAs (less than $50/lb compared to NiTi which is $200/lb due to difficulties in processing), it is anticipated that the findings of the study could be implemented in real infrastructures made of concrete, asphalt concrete, and other complex large infrastructure. Low-cost Fe-SMAs and other multifunctional materials can be considered as a replacement for components made of steel (e ...


Biopolymer-Stabilized Earth Materials For Resilient And Adaptable Infrastructures, Sherif Abdelaziz, Dilip Gersappe, Dilip Rafailovich Sep 2019

Biopolymer-Stabilized Earth Materials For Resilient And Adaptable Infrastructures, Sherif Abdelaziz, Dilip Gersappe, Dilip Rafailovich

Department of Civil Engineering Faculty Publications

Earth dams and levees are constructed and retrofitted nowadays using the same materials that were used in the past, clays and sands. Despite the current advances in engineering, designing and constructing these critical infrastructure, earthen dams and levees continue to suffer from the same challenges over the years. These challenges include internal and surface erosions, loss of stability due to moisture migration, and inabilities to self-heal potential failure points. This project focuses on the use of biopolymers as additives to strengthen earthen dams and levees targeting an overall increase in their resilience.

Explicitly, the report for Milestone 3 presented the ...


Effect Of Anisotropic Elasticity On Dislocation Pile-Ups At Grain Boundaries, Xiaolei Chen, Stéphane Berbenni, Christian Motz, Thiebaud Richeton Sep 2019

Effect Of Anisotropic Elasticity On Dislocation Pile-Ups At Grain Boundaries, Xiaolei Chen, Stéphane Berbenni, Christian Motz, Thiebaud Richeton

Nanomechanical Testing in Materials Research and Development VII

This study deals with in-situ micromechanical tests of micron-sized bi-crystals and observations coupling SEM, AFM and EBSD. Different FCC bi-crystals are obtained from FIB machining. A SEM in-situ compression test with a low strain is performed on a micron-sized bi-crystal in order to induce single slip deformation. Spatial variations in the surface step height due to dislocation activity in localized slip bands terminating at the grain boundary (GB) are measured by AFM. This allows the determination of the Burgers vector distribution and hence the dislocation positions in the pile-up as shown in Figure 1. Furthermore, local misorientation along slip bands ...


High Throughput Screening Of 3d Printable Resins: Adjusting The Surface And Catalytic Properties Of Multifunctional Architectures, J. Sebastián Manzano, Hsin Wang, Igor I. Slowing Sep 2019

High Throughput Screening Of 3d Printable Resins: Adjusting The Surface And Catalytic Properties Of Multifunctional Architectures, J. Sebastián Manzano, Hsin Wang, Igor I. Slowing

Chemistry Publications

Identification of 3D printable materials is crucial to expand the breadth of physical and chemical properties attainable by additive manufacturing. Stereolithography (SLA), a widespread 3D printing method based on resin photo-polymerization, is ideally suited for exploring a large variety of monomers to produce functional three-dimensional solids of diverse properties. However, for most of the commercially available SLA 3D printers, screening monomers and resin compositions requires large volumes (~150 mL) in each printing cycle, making the process costly and inefficient. Herein, a high throughput block (HTB) adaptor was developed to screen arrays of monomers and resin compositions, consuming lower volumes (< 2 mL) and less time per print (< 1/16 based on a 44 matrix) than using the original hardware. Using this approach, a library of materials with different surface hydrophobicities were 3D printed by including long chain acrylates in the resins. In addition, several metal salts were dissolved in an acrylic acid-based resin, 3D printed and screened as heterogeneous catalysts for the selective aerobic oxidation of benzyl alcohol to benzaldehyde. Cu(II)-based resins produced the most active structures. Combinations of Cu(II) and long chain acrylate monomers were then used to 3D print complex catalytic architectures with varying degrees of hydrophobicity. Linear relationships were observed between 3D printed surface area, surface hydrophobicity and catalyst performance. For a high surface Schwarz P topology ca. 60 % enhancement in the catalytic activity of Cu(II) was attained by replacing the parent resin with one containing hydrophobic isodecyl groups, indicating that the immediate environment of the catalytic site affected its performance. The HTB enables fast screening of resins for 3D printing multifunctional architectures with intrinsic catalytic activity, tunable surface properties, and minimal waste.


Conference Program, Jon Molina-Aldareguia Sep 2019

Conference Program, Jon Molina-Aldareguia

Nanomechanical Testing in Materials Research and Development VII

No abstract provided.


High-Power Biofuel Cells Based On Threedimensional Reduced Graphene Oxide/ Carbon Nanotube Micro-Arrays, Yin Song, Chunlei Wang Sep 2019

High-Power Biofuel Cells Based On Threedimensional Reduced Graphene Oxide/ Carbon Nanotube Micro-Arrays, Yin Song, Chunlei Wang

Department of Mechanical and Materials Engineering

Miniaturized enzymatic biofuel cells (EBFCs) with high cell performance are promising candidates for powering next-generation implantable medical devices. Here, we report a closed-loop theoretical and experimental study on a micro EBFC system based on three-dimensional (3D) carbon micropillar arrays coated with reduced graphene oxide (rGO), carbon nanotubes (CNTs), and a biocatalyst composite. The fabrication process of this system combines the top–down carbon microelectromechanical systems (C-MEMS) technique to fabricate the 3D micropillar array platform and bottom–up electrophoretic deposition (EPD) to deposit the reduced rGO/CNTs/enzyme onto the electrode surface. The Michaelis–Menten constant KM of 2.1 mM ...


Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson Sep 2019

Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson

Protocols and Reports

The process of transferring a monolayer of graphene using two different concentrations of sodium hydroxide (NaOH) solution unto a silicon dioxide (SiO2) coated Si chip using electrochemistry was performed. The transfer process is crucial for the delamination of a continuous graphene monolayer film from copper foil. After examining and inspecting the integrity of the graphene monolayer, it was observed that the lower concentration to NaOH led to slower rate of hydrogen bubble generation; this condition was found to be less destructive and yielded a graphene film with fewer visible tears.


Force Oscillations Distort Avalanche Shapes, Louis W. Mcfaul, Wendelin J. Wright, Jordan Sickle, Karin A. Dahmen Sep 2019

Force Oscillations Distort Avalanche Shapes, Louis W. Mcfaul, Wendelin J. Wright, Jordan Sickle, Karin A. Dahmen

Faculty Journal Articles

Contradictory scaling behavior in experiments testing the principle of universality may be due to external oscillations. Thus, the effect of damped oscillatory external forces on slip avalanches in slowly deformed solids is simulated using a mean-field model. Akin to a resonance effect, oscillatory driving forces change the dynamics of avalanches with durations close to the oscillation period. This problem can be avoided by tuning mechanical resonance frequencies away from the range of the inverse avalanche durations. The results provide critical guidance for experimental tests for universality and a quantitative understanding of avalanche dynamics under a wide range of driving conditions.


Mitigating Reflective Cracking Through The Use Of A Ductile Concrete Interlayer, Qian Zhang, Mohammad Khattak, Adway Das Sep 2019

Mitigating Reflective Cracking Through The Use Of A Ductile Concrete Interlayer, Qian Zhang, Mohammad Khattak, Adway Das

Publications

Reflective cracking is considered one of the most important issues that causes premature deterioration of composite pavements. Many types of mitigation methods have been studied in the past. However, they are either not effective in delaying the reflective cracking, or they only extend the service life by a few years. To address this critical issue and significantly extend the service life of the composite pavement, in this research, a ductile interlayer made of engineered cementitious composites (ECC) was proposed. It was hypothesized that by adding a thin layer of highly ductile ECC material between the existing pavement and overlay, reflective ...


Toward Non-Corrosion And Highly Sustainable Structural Members By Using Ultra-High-Performance Materials For Transportation Infrastructure, Shih-Ho Chao, Ashish Karmacharya Sep 2019

Toward Non-Corrosion And Highly Sustainable Structural Members By Using Ultra-High-Performance Materials For Transportation Infrastructure, Shih-Ho Chao, Ashish Karmacharya

Publications

This research focused on investigating a highly sustainable and efficient reinforced concrete structural member for future infrastructure by utilizing emerging high-performance materials. These materials include ultra-high-performance fiber-reinforced concrete (UHP-FRC) and corrosion-resistant high-strength fiber-reinforced polymer (FRP) bars. Four reduced scale UHP-FRC specimens were tested under large displacement reversals to prove the proposed new ductile-concrete strong-reinforcement (DCSR) design concept by fully utilizing these ultra-high-performance materials. Micro steel fibers were incorporated into three specimens and ultra-high molecular weight polyethylene fibers were blended into the fourth specimen. One specimen with ASTM A1035 MMFX high-strength steel rebars, one with high-strength glass fiber reinforced polymer (GFRP ...


Investigation Of Physical And Dynamic Properties Of High Porous Concrete, Ildar Akhmadullin Sep 2019

Investigation Of Physical And Dynamic Properties Of High Porous Concrete, Ildar Akhmadullin

Publications

This project pursued two main objectives: (1) providing opportunities to Baton Rouge Community College (BRCC) students to develop hands-on laboratory skills and exposure to the transportation field, and (2) investigating porous concrete properties. Several BRCC student groups performed the work presented within this report; students prepared samples with different porosity and permeability according to standard specifications. The testing of the samples was performed at the Louisiana Transportation Research Center (LTRC) facility under the supervision of LTRC specialists. Findings indicate that the porosity of samples is backward proportional to the compression strength. This function is not linear but can be estimated ...


Toward Non-Corrosion And Highly Sustainable Structural Members By Using Ultra-High-Performance Materials For Transportation Infrastructure, Shih-Ho Chao, Ashish Karmacharya Sep 2019

Toward Non-Corrosion And Highly Sustainable Structural Members By Using Ultra-High-Performance Materials For Transportation Infrastructure, Shih-Ho Chao, Ashish Karmacharya

Data

Corresponding data set for Tran-SET Project No. 18STUTA01. Abstract of the final report is stated below for reference:

"This research focused on investigating a highly sustainable and efficient reinforced concrete structural member for future infrastructure by utilizing emerging high-performance materials. These materials include ultra-high-performance fiber-reinforced concrete (UHP-FRC) and corrosion-resistant high-strength fiber-reinforced polymer (FRP) bars. Four reduced scale UHP-FRC specimens were tested under large displacement reversals to prove the proposed new ductile-concrete strong-reinforcement (DCSR) design concept by fully utilizing these ultra-high-performance materials. Micro steel fibers were incorporated into three specimens and ultra-high molecular weight polyethylene fibers were blended into the fourth ...


Assessing Bio-Based Fog Seal For Asphalt Pavement Preservation, Bo Yang, Yang Zhang, Halil Ceylan, Sunghwan Kim Sep 2019

Assessing Bio-Based Fog Seal For Asphalt Pavement Preservation, Bo Yang, Yang Zhang, Halil Ceylan, Sunghwan Kim

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

All types of roads, including those with asphalt pavements, steadily deteriorate over time because of repeated mechanical (traffic) and climatic loadings. Pavement preservation consists of applying a suitable treatment on deteriorated roads to maintain good conditions and extend their service lives (1, 2). Fog seal is a low-cost application of liquid asphalt or emulsion derived from petroleum or coal tar to slow down microcracking propagation, prevent oxidation, and seal against water infiltration. The conventional fog sealants need heating before spraying on the pavement surface, and the recommended spray temperature should be between 52°C and 71°C (125°F and ...


A Novel Performance-Based Economic Analysis Approach: Case Study Of Iowa Low-Volume Roads, Sajjad Satvati, Jeramy C. Ashlock, Ali Nahvi, Charles T. Jahren, Bora Cetin, Halil Ceylan Sep 2019

A Novel Performance-Based Economic Analysis Approach: Case Study Of Iowa Low-Volume Roads, Sajjad Satvati, Jeramy C. Ashlock, Ali Nahvi, Charles T. Jahren, Bora Cetin, Halil Ceylan

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Approximately 110,000 km (68,400 mi) of granular roadways exist in the 183,500-km (114,000-mi) road network in the state of Iowa, and operation and maintenance of these roadways costs roughly US$270 million annually. The major maintenance costs of these roads are aggregate cost and hauling costs from the quarry to the site. Accordingly, acquiring a costeffective and high-performance surface material to be utilized in granular roadways can be a challenge. In this study, three conventional granular roadway materials and four coarser aggregate materials from different quarries were used to construct seven test sections to assess their ...


Mitigating Reflective Cracking Through The Use Of A Ductile Concrete Interlayer, Qian Zhang, Mohammad Khattak, Adway Das Sep 2019

Mitigating Reflective Cracking Through The Use Of A Ductile Concrete Interlayer, Qian Zhang, Mohammad Khattak, Adway Das

Data

Corresponding data set for Tran-SET Project No. 18PLSU13. Abstract of the final report is stated below for reference:

"Reflective cracking is considered one of the most important issues that causes premature deterioration of composite pavements. Many types of mitigation methods have been studied in the past. However, they are either not effective in delaying the reflective cracking, or they only extend the service life by a few years. To address this critical issue and significantly extend the service life of the composite pavement, in this research, a ductile interlayer made of engineered cementitious composites (ECC) was proposed. It was hypothesized ...


Development Of Geopolymer-Based Cement And Soil Stabilizers For Transportation Infrastructure, Miladin Radovic, Anand Puppala Sep 2019

Development Of Geopolymer-Based Cement And Soil Stabilizers For Transportation Infrastructure, Miladin Radovic, Anand Puppala

Publications

Geopolymer Cement (GPC) has drawn much attention in the recent years as an alternative to Ordinary Portland Cement (OPC) for soil stabilization, pavements, bridges and other transportation structures due to their good mechanical properties in comparison to OPC. In addition, GPC can be processed at room temperatures from aqueous solutions of waste materials (e.g. fly ash) or abundant natural sources (e.g. clay), thereby significantly reducing CO2 production associated with processing of OPC. As such, GPC proves to be a more sustainable and environmentally friendly alternative than OPC. This research explores methods to develop GPC with desired properties and ...


Non-Fermi-Liquid Types Of Behavior Associated With A Magnetic Quantum Critical Point In Sr(Co1-Xnix)(2)As-2 Single Crystals, Nediadath S. Sangeetha, Lin-Lin Wang, Andrei V. Smirnov, Volodymyr Smetana, A. V. Mudring, Duane D. Johnson, Makariy A. Tanatar, Ruslan Prozorov, David C. Johnston Sep 2019

Non-Fermi-Liquid Types Of Behavior Associated With A Magnetic Quantum Critical Point In Sr(Co1-Xnix)(2)As-2 Single Crystals, Nediadath S. Sangeetha, Lin-Lin Wang, Andrei V. Smirnov, Volodymyr Smetana, A. V. Mudring, Duane D. Johnson, Makariy A. Tanatar, Ruslan Prozorov, David C. Johnston

Materials Science and Engineering Publications

The compound SrCo2As2 with the body-centered tetragonal ThCr2Si2 structure is known to remain paramagnetic down to a temperature T=0.05 K, but inelastic neutron scattering studies have shown that both ferromagnetic (FM) and antiferromagnetic (AFM) fluctuations occur in single crystals. Thus it is of interest to study how the magnetism evolves on doping SrCo2As2. Previous work on polycrystalline samples of Sr(Co1−xNix)2As2 indicated the development of AFM order for 0Ab initioelectronic-structure calculations for x=0 and 0.15 indicate that a flat band with a peak in the density of states just above the Fermi energy is ...