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Full-Text Articles in Mechanical Engineering

Development And Validation Of A Nonlinear Dynamic Model For Tuned Liquid Multiple Columns Dampers, Liang Cao, Yongqiang Gong, Filippo Ubertini, Hao Wu, An Chen, Simon Laflamme Nov 2020

Development And Validation Of A Nonlinear Dynamic Model For Tuned Liquid Multiple Columns Dampers, Liang Cao, Yongqiang Gong, Filippo Ubertini, Hao Wu, An Chen, Simon Laflamme

Civil, Construction and Environmental Engineering Publications

The tuned liquid column damper (TLCD), a passive damping device consisting of a large U-tube with oscillating liquid, has been shown to be effective at mitigating structural responses under natural hazards. Aside from their bandwidth-limited mitigation capabilities, a key limitation of TLCDs is in their large geometries that occupy large space often at prime locations. A solution is to implement multi-columned versions, termed tuned liquid multiple columns dampers (TLMCDs), which have the potential to be tuned to multiple frequencies and occupy less space by leveraging the multiple columns to allow fluid movement. However, mathematical models characterizing their dynamic behavior must ...


Proof-Of-Concept Of High-Pressure Torrefaction For Improvement Of Pelletized Biomass Fuel Properties And Process Cost Reduction, Bartosz Matyjewicz, Kacper Świechowski, Jacek A. Koziel, Andrzej Białowiec Sep 2020

Proof-Of-Concept Of High-Pressure Torrefaction For Improvement Of Pelletized Biomass Fuel Properties And Process Cost Reduction, Bartosz Matyjewicz, Kacper Świechowski, Jacek A. Koziel, Andrzej Białowiec

Agricultural and Biosystems Engineering Publications

This paper provides a comprehensive description of the new approach to biomass torrefaction under high-pressure conditions. A new type of laboratory-scale high-pressure reactor was designed and built. The aim of the study was to compare the high-pressure torrefaction with conventional near atmospheric pressure torrefaction. Specifically, we investigated the torrefaction process influence on the fuel properties of wooden-pellet for two different pressure regimes up to 15 bar. All torrefaction processes were conducted at 300 °C, at 30 min of residence time. The initial analysis of the increased pressure impact on the torrefaction parameters: mass yields, energy densification ratio, energy yield, process ...


Synergy Of Thermochemical Treatment Of Dried Distillers Grains With Solubles With Bioethanol Production For Increased Sustainability And Profitability, Samuel O’Brien, Jacek A. Koziel, Chumki Banik, Andrzej Białowiec Sep 2020

Synergy Of Thermochemical Treatment Of Dried Distillers Grains With Solubles With Bioethanol Production For Increased Sustainability And Profitability, Samuel O’Brien, Jacek A. Koziel, Chumki Banik, Andrzej Białowiec

Agricultural and Biosystems Engineering Publications

The bioethanol industry continues improving sustainability, specifically focused on plant energy and GHG emission management. Dried distiller grains with solubles (DDGS) is a byproduct of ethanol fermentation and is used for animal feed. DDGS is a relatively low-value bulk product that decays, causes odor, and is challenging to manage. The aim of this research was to find an alternative, value-added-type concept for DDGS utilization. Specifically, we aimed to explore the techno-economic feasibility of torrefaction, i.e., a thermochemical treatment of DDGS requiring low energy input, less sophisticated equipment, and resulting in fuel-quality biochar. Therefore, we developed a research model that ...


Challenges And Opportunities In Machine-Augmented Plant Stress Phenotyping, Arti Singh, Sarah Jones, Baskar Ganapathysubramanian, Soumik Sarkar, Daren S. Mueller, Kulbir Sandhu, Koushik Nagasubramanian Aug 2020

Challenges And Opportunities In Machine-Augmented Plant Stress Phenotyping, Arti Singh, Sarah Jones, Baskar Ganapathysubramanian, Soumik Sarkar, Daren S. Mueller, Kulbir Sandhu, Koushik Nagasubramanian

Mechanical Engineering Publications

Plant stress phenotyping is essential to select stress-resistant varieties and develop better stress-management strategies. Standardization of visual assessments and deployment of imaging techniques have improved the accuracy and reliability of stress assessment in comparison with unaided visual measurement. The growing capabilities of machine learning (ML) methods in conjunction with image-based phenotyping can extract new insights from curated, annotated, and high-dimensional datasets across varied crops and stresses. We propose an overarching strategy for utilizing ML techniques that methodically enables the application of plant stress phenotyping at multiple scales across different types of stresses, program goals, and environments.


Influence Of Brain-Scalp Distance On Focality Of The Quadruple Butterfly Coil For Transcranial Magnetic Stimulation, Oluwaponmile F. Afuwape, Joseph Boldrey, Priyam Rastogi, Sarah A. Bentil, David C. Jiles Aug 2020

Influence Of Brain-Scalp Distance On Focality Of The Quadruple Butterfly Coil For Transcranial Magnetic Stimulation, Oluwaponmile F. Afuwape, Joseph Boldrey, Priyam Rastogi, Sarah A. Bentil, David C. Jiles

Electrical and Computer Engineering Publications

Transcranial Magnetic Stimulation (TMS) is a neuromodulation technique that non-invasively depolarizes neurons in the brain. During TMS, a pulse (or multiple pulses) of a time-varying magnetic field (H) is delivered to the brain using specialized coils. The Quadruple Butterfly Coil (QBC) is a novel coil design that shows increased focality of the induced electric field over that of the standard figure-of-eight (FoE) coil. Using 50 different head models created from MRI scans of healthy individuals, our research investigated the role that brain-scalp distance (BSD) plays in the brain’s response to the magnetic fields generated by the QBC and FoE ...


Leaf Angle Extractor: A High‐Throughput Image Processing Framework For Leaf Angle Measurements In Maize And Sorghum, Sunil K. Kenchanmane Raju, Miles Adkins, Alex Enersen, Daniel Santana De Carvalho, Anthony J. Studer, Baskar Ganapathysubramanian, Patrick S. Schnable, James C. Schnable Aug 2020

Leaf Angle Extractor: A High‐Throughput Image Processing Framework For Leaf Angle Measurements In Maize And Sorghum, Sunil K. Kenchanmane Raju, Miles Adkins, Alex Enersen, Daniel Santana De Carvalho, Anthony J. Studer, Baskar Ganapathysubramanian, Patrick S. Schnable, James C. Schnable

Mechanical Engineering Publications

PREMISE: Maize yields have significantly increased over the past half-century owing to advances in breeding and agronomic practices. Plants have been grown in increasingly higher densities due to changes in plant architecture resulting in plants with more upright leaves, which allows more efficient light interception for photosynthesis. Natural variation for leaf angle has been identified in maize and sorghum using multiple mapping populations. However, conventional phenotyping techniques for leaf angle are low throughput and labor intensive, and therefore hinder a mechanistic understanding of how the leaf angle of individual leaves changes over time in response to the environment.

METHODS: High-throughput ...


Automated Trichome Counting In Soybean Using Advanced Image‐Processing Techniques, Seyed Vahid Mirnezami, Therin Young, Teshale Assefa, Shelby Prichard, Koushik Nagasubramanian, Kulbir Sandhu, Soumik Sarkar, Sriram Sundararajan, Matthew E. O'Neal, Baskar Ganapathysubramanian, Arti Singh Jul 2020

Automated Trichome Counting In Soybean Using Advanced Image‐Processing Techniques, Seyed Vahid Mirnezami, Therin Young, Teshale Assefa, Shelby Prichard, Koushik Nagasubramanian, Kulbir Sandhu, Soumik Sarkar, Sriram Sundararajan, Matthew E. O'Neal, Baskar Ganapathysubramanian, Arti Singh

Mechanical Engineering Publications

Premise Trichomes are hair‐like appendages extending from the plant epidermis. They serve many important biotic roles, including interference with herbivore movement. Characterizing the number, density, and distribution of trichomes can provide valuable insights on plant response to insect infestation and define the extent of plant defense capability. Automated trichome counting would speed up this research but poses several challenges, primarily because of the variability in coloration and the high occlusion of the trichomes.

Methods and Results We developed a simplified method for image processing for automated and semi‐automated trichome counting. We illustrate this process using 30 leaves from ...


Low-Temperature Pyrolysis Of Municipal Solid Waste Components And Refuse-Derived Fuel—Process Efficiency And Fuel Properties Of Carbonized Solid Fuel, Kacper Swiechowski, Ewa Syguła, Jacek A. Koziel, Paweł Stepien, Szymon Kugler, Piotr Manczarski, Andrzej Białowiec Jun 2020

Low-Temperature Pyrolysis Of Municipal Solid Waste Components And Refuse-Derived Fuel—Process Efficiency And Fuel Properties Of Carbonized Solid Fuel, Kacper Swiechowski, Ewa Syguła, Jacek A. Koziel, Paweł Stepien, Szymon Kugler, Piotr Manczarski, Andrzej Białowiec

Agricultural and Biosystems Engineering Publications

New technologies to valorize refuse-derived fuels (RDFs) will be required in the near future due to emerging trends of (1) the cement industry’s demands for high-quality alternative fuels and (2) the decreasing calorific value of the fuels derived from municipal solid waste (MSW) and currently used in cement/incineration plants. Low-temperature pyrolysis can increase the calorific value of processed material, leading to the production of value-added carbonized solid fuel (CSF). This dataset summarizes the key properties of MSW-derived CSF. Pyrolysis experiments were completed using eight types of organic waste and their two RDF mixtures. Organic waste represented common morphological ...


Waste To Energy: Solid Fuel Production From Biogas Plant Digestate And Sewage Sludge By Torrefaction-Process Kinetics, Fuel Properties, And Energy Balance, Kacper Świechowski, Martyna Hnat, Paweł Stępień, Sylwia Stegenta-Dąbrowska, Szymon Kugler, Jacek A. Koziel, Andrzej Białowiec Jun 2020

Waste To Energy: Solid Fuel Production From Biogas Plant Digestate And Sewage Sludge By Torrefaction-Process Kinetics, Fuel Properties, And Energy Balance, Kacper Świechowski, Martyna Hnat, Paweł Stępień, Sylwia Stegenta-Dąbrowska, Szymon Kugler, Jacek A. Koziel, Andrzej Białowiec

Agricultural and Biosystems Engineering Publications

Sustainable solutions are needed to manage increased energy demand and waste generation. Renewable energy production from abundant sewage sludge (SS) and digestate (D) from biogas is feasible. Concerns about feedstock contamination (heavy metals, pharmaceuticals, antibiotics, and antibiotic-resistant bacteria) in SS and D limits the use (e.g., agricultural) of these carbon-rich resources. Low temperature thermal conversion that results in carbonized solid fuel (CSF) has been proposed as sustainable waste utilization. The aim of the research was to investigate the feasibility of CSF production from SS and D via torrefaction. The CSF was produced at 200~300 °C (interval of 20 ...


Soybean Root System Architecture Trait Study Through Genotypic, Phenotypic, And Shape-Based Clusters, Kevin G. Falk, Talukder Zaki Jubery, Jamie A. O’Rourke, Arti Singh, Soumik Sarkar, Baskar Ganapathysubramanian, Asheesh K. Singh Jun 2020

Soybean Root System Architecture Trait Study Through Genotypic, Phenotypic, And Shape-Based Clusters, Kevin G. Falk, Talukder Zaki Jubery, Jamie A. O’Rourke, Arti Singh, Soumik Sarkar, Baskar Ganapathysubramanian, Asheesh K. Singh

Mechanical Engineering Publications

We report a root system architecture (RSA) traits examination of a larger scale soybean accession set to study trait genetic diversity. Suffering from the limitation of scale, scope, and susceptibility to measurement variation, RSA traits are tedious to phenotype. Combining 35,448 SNPs with an imaging phenotyping platform, 292 accessions (replications=14) were studied for RSA traits to decipher the genetic diversity. Based on literature search for root shape and morphology parameters, we used an ideotype-based approach to develop informative root (iRoot) categories using root traits. The RSA traits displayed genetic variability for root shape, length, number, mass, and angle ...


Leidenfrost Behavior In Drop-Wall Impacts At Combustor-Relevant Ambient Pressures, Abhijeet Chausalkar, Chol-Bum M. Kweon, Song-Charng Kong, James B. Michael Jun 2020

Leidenfrost Behavior In Drop-Wall Impacts At Combustor-Relevant Ambient Pressures, Abhijeet Chausalkar, Chol-Bum M. Kweon, Song-Charng Kong, James B. Michael

Mechanical Engineering Publications

Liquid-fueled combustion systems demand optimal performance over a range of operating conditions—requiring predictable fuel injection events, spray breakup, and vaporization across a range of temperatures and pressures. In direct injection combustors, these sprays impinge directly on combustion chamber surfaces. Although the outcome of fuel droplets impacting a wall is primarily driven by the wall temperature and the Leidenfrost effect, the shifting liquid-vapor saturation point with pressure may influence the droplet-wall heat transfer rate and transition from nucleate to film boiling. In this paper, the role of ambient pressure on the droplet impact regimes, spreading rate, and droplet rebound velocity ...


Multiscale Modeling Reveals The Cause Of Surface Stress Change On Microcantilevers Due To Alkanethiol Sam Adsorption, Yue Zhao, Agnivo Gosai, Kyungho Kang, Pranav Shrotriya May 2020

Multiscale Modeling Reveals The Cause Of Surface Stress Change On Microcantilevers Due To Alkanethiol Sam Adsorption, Yue Zhao, Agnivo Gosai, Kyungho Kang, Pranav Shrotriya

Mechanical Engineering Publications

Experimental results show that the adsorption of the self assembled monolayers (SAMs) on a gold surface induces surface stress change that cause a deformation of the underlying substrate. However, the exact mechanism of stress development is yet to be elucidated. In the present study, multiscale computational models based on molecular dynamics (MD) simulations are applied to study the mechanism governing surface stress change. Distinct mechanisms for adsorption induced surface deformation, namely inter chain repulsion and thiol-gold interaction driven gold surface reconstruction, are investigated. Two different inter-atomic potentials, embedded atom method (EAM) and surface embedded atom method (SEAM), are used in ...


Crystallographic Facet Selective Her Catalysis: Exemplified In Fep And Nip2 Single Crystals, Bryan Owens-Baird, Juliana P.S. Sousa, Yasmine Ziouani, Dmitri Y. Petrovykh, Nikolai A. Zarkevich, Duane D. Johnson, Yury V. Kolen'ko, Kirill Kovnir Apr 2020

Crystallographic Facet Selective Her Catalysis: Exemplified In Fep And Nip2 Single Crystals, Bryan Owens-Baird, Juliana P.S. Sousa, Yasmine Ziouani, Dmitri Y. Petrovykh, Nikolai A. Zarkevich, Duane D. Johnson, Yury V. Kolen'ko, Kirill Kovnir

Ames Laboratory Accepted Manuscripts

How the crystal structures of ordered transition-metal phosphide catalysts affect the hydrogen-evolution reaction (HER) is investigated by measuring the anisotropic catalytic activities of selected crystallographic facets on large (mm-sized) single crystals of iron-phosphide (FeP) and monoclinic nickel-diphosphide (m-NiP2). We find that different crystallographic facets exhibit distinct HER activities, in contrast to a commonly held assumption of severe surface restructuring during catalytic activity. Moreover, density-functional-theory-based computational studies show that the observed facet activity correlates well with the H-binding energy to P atoms on specific surface terminations. Direction dependent catalytic properties of two different phosphides with different transition metals, crystal structures, and ...


Single-Atom-Layer Traps In A Solid Electrolyte For Lithium Batteries, Feng Zhu, Md Shafiqul Islam, Lin Zhou, Zhenqi Gu, Ting Liu, Xinchao Wang, Jun Luo, Ce-Wen Nan, Yifei Mo, Cheng Ma Apr 2020

Single-Atom-Layer Traps In A Solid Electrolyte For Lithium Batteries, Feng Zhu, Md Shafiqul Islam, Lin Zhou, Zhenqi Gu, Ting Liu, Xinchao Wang, Jun Luo, Ce-Wen Nan, Yifei Mo, Cheng Ma

Ames Laboratory Accepted Manuscripts

In order to fully understand the lithium-ion transport mechanism in solid electrolytes for batteries, not only the periodic lattice but also the non-periodic features that disrupt the ideal periodicity must be comprehensively studied. At present only a limited number of non-periodic features such as point defects and grain boundaries are considered in mechanistic studies. Here, we discover an additional type of non-periodic feature that significantly influences ionic transport; this feature is termed a “single-atom-layer trap” (SALT). In a prototype solid electrolyte Li0.33La0.56TiO3, the single-atom-layer defects that form closed loops, i.e., SALTs, are found ubiquitous by atomic-resolution electron ...


Surge And Stall Detection Using Acoustic Analysis For Gas Turbine Hybrid Cycles, Keishaly Cabrera Cruz, Paolo Pezzini, Lawrence Shadle, Kenneth Bryden Apr 2020

Surge And Stall Detection Using Acoustic Analysis For Gas Turbine Hybrid Cycles, Keishaly Cabrera Cruz, Paolo Pezzini, Lawrence Shadle, Kenneth Bryden

Ames Laboratory Accepted Manuscripts

Compressor dynamics were studied in a gas turbine—fuel cell hybrid power system having a larger compressor volume than traditionally found in gas turbine systems. This larger compressor volume adversely affects the surge margin of the gas turbine. Industrial acoustic sensors were placed near the compressor to identify when the equipment was getting close to the surge line. Fast Fourier transform (FFT) mathematical analysis was used to obtain spectra representing the probability density across the frequency range (0–5000 Hz). Comparison between FFT spectra for nominal and transient operations revealed that higher amplitude spikes were observed during incipient stall at ...


Enhancing The Conductivity Of Cell-Laden Alginate Microfibers With Aqueous Graphene For Neural Applications, Marilyn C. Mcnamara, Amir Ehsan Niaraki-Asli, Jingshuai Guo, Jasmin Okuzono, Reza Montazami, Nicole N. Hashemi Mar 2020

Enhancing The Conductivity Of Cell-Laden Alginate Microfibers With Aqueous Graphene For Neural Applications, Marilyn C. Mcnamara, Amir Ehsan Niaraki-Asli, Jingshuai Guo, Jasmin Okuzono, Reza Montazami, Nicole N. Hashemi

Mechanical Engineering Publications

Microfluidically manufacturing graphene-alginate microfibers create possibilities for encapsulating rat neural cells within conductive 3D tissue scaffolding to enable the creation of real-time 3D sensing arrays with high physiological relavancy. Cells are encapsulated using the biopolymer alginate, which is combined with graphene to create a cell-containing hydrogel with increased electrical conductivity. Resulting novel alginate-graphene microfibers showed a 2.5-fold increase over pure alginate microfibers, but did not show significant differences in size and porosity. Cells encapsulated within the microfibers survive for up to 8 days, and maintain ~20% live cells over that duration. The biocompatible aqueous graphene suspension used in this ...


Similarity Evaluation Of Topography Measurement Results By Different Optical Metrology Technologies For Additive Manufactured Parts, Yi Zheng, Xiao Zhang, Shaodong Wang, Qing Li, Hantang Qin, Beiwen Li Mar 2020

Similarity Evaluation Of Topography Measurement Results By Different Optical Metrology Technologies For Additive Manufactured Parts, Yi Zheng, Xiao Zhang, Shaodong Wang, Qing Li, Hantang Qin, Beiwen Li

Industrial and Manufacturing Systems Engineering Publications

The surface topographic measurements can be used by the additive manufacturing (AM) industry for in-situ quality inspection. However, disagreements may arise when we use different technologies to measure the topography of the same sample surface due to noise, sampling or optical properties of the sample surface, which may cause miscommunications or confusions between manufacturers. Thus, proposing methods for rating the similarities to match surface topographic data measured by various optical techniques is of crucial importance. This research investigates similarity evaluation methods for three-dimensional point-cloud topography data acquired by different technologies. Two different optical techniques (focus variation microscopy and structured light ...


Wind Turbine And Turbomachinery Computational Analysis With The Ale And Space-Time Variational Multiscale Methods And Isogeometric Discretization, Yuri Bazilevs, Kenji Takizawa, Tayfun E. Tezduyar, Ming-Chen Hsu, Yuto Otoguro, Hiroki Mochizuki, Michael C.H. Wu Mar 2020

Wind Turbine And Turbomachinery Computational Analysis With The Ale And Space-Time Variational Multiscale Methods And Isogeometric Discretization, Yuri Bazilevs, Kenji Takizawa, Tayfun E. Tezduyar, Ming-Chen Hsu, Yuto Otoguro, Hiroki Mochizuki, Michael C.H. Wu

Mechanical Engineering Publications

The challenges encountered in computational analysis of wind turbines and turbomachinery include turbulent rotational flows, complex geometries, moving boundaries and interfaces, such as the rotor motion, and the fluid-structure interaction (FSI), such as the FSI between the wind turbine blade and the air. The Arbitrary Lagrangian-Eulerian (ALE) and Space-Time (ST) Variational Multiscale (VMS) methods and isogeometric discretization have been effective in addressing these challenges. The ALE-VMS and ST-VMS serve as core computational methods. They are supplemented with special methods like the Slip Interface (SI) method and ST Isogeometric Analysis with NURBS basis functions in time. We describe the core and ...


Fabrication Of 2d And 3d High-Resolution Binder-Free Graphene Circuits Using A Microfluidic Approach For Sensor Applications, Metin Uz, Matthew T. Lentner, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, John Hondred, Eric Mach, Jonathan C. Claussen, Surya K. Mallapragada Feb 2020

Fabrication Of 2d And 3d High-Resolution Binder-Free Graphene Circuits Using A Microfluidic Approach For Sensor Applications, Metin Uz, Matthew T. Lentner, Kyle Jackson, Maxsam S. Donta, Juhyung Jung, John Hondred, Eric Mach, Jonathan C. Claussen, Surya K. Mallapragada

Chemical and Biological Engineering Publications

In this study, a simple microfluidic method, which can be universally applied to different rigid or flexible substrates, was developed to fabricate high-resolution, conductive, 2D and 3D microstructured graphene-based electronic circuits. The method involves controlled and selective filling of microchannels on substrate surfaces with a conductive binder-free graphene nanoplatelets (GNP) solution. The ethanol-thermal reaction of GNP solution at low temperatures (~75 °C) prior to microchannel filling (pre-heating) further reduces GNP, enhances conductivity, reduces sheet resistance (~0.05 kΩ sq-1), enables room temperature fabrication and eliminates harsh post-processing, which makes this fabrication technique compatible with degradable substrates. This method can also ...


Teleporting Through Virtual Environments: Effects Of Path Scale And Environment Scale On Spatial Updating, Jonathan W. Kelly, Alec G. Ostrander, Alex F. Lim, Lucia A. Cherep, Stephen B. Gilbert Feb 2020

Teleporting Through Virtual Environments: Effects Of Path Scale And Environment Scale On Spatial Updating, Jonathan W. Kelly, Alec G. Ostrander, Alex F. Lim, Lucia A. Cherep, Stephen B. Gilbert

Psychology Publications

Virtual reality systems typically allow users to physically walk and turn, but virtual environments (VEs) often exceed the available walking space. Teleporting has become a common user interface, whereby the user aims a laser pointer to indicate the desired location, and sometimes orientation, in the VE before being transported without self-motion cues. This study evaluated the influence of rotational self-motion cues on spatial updating performance when teleporting, and whether the importance of rotational cues varies across movement scale and environment scale. Participants performed a triangle completion task by teleporting along two outbound path legs before pointing to the unmarked path ...


Subsurface Cooling Rates And Microstructural Response During Laser Based Metal Additive Manufacturing, Vivek Thampy, Anthony Y. Fong, Nicholas P. Calta, Jenny Wang, Aiden A. Martin, Philip J. Depond, Andrew M. Kiss, Gabe Guss, Qingfeng Xing, Ryan T. Ott, Anthony Van Buuren, Michael F. Toney, Johanna Nelson Weker, Matthew J. Kramer, Manyalibo J. Matthews, Christopher J. Tassone, Kevin H. Stone Feb 2020

Subsurface Cooling Rates And Microstructural Response During Laser Based Metal Additive Manufacturing, Vivek Thampy, Anthony Y. Fong, Nicholas P. Calta, Jenny Wang, Aiden A. Martin, Philip J. Depond, Andrew M. Kiss, Gabe Guss, Qingfeng Xing, Ryan T. Ott, Anthony Van Buuren, Michael F. Toney, Johanna Nelson Weker, Matthew J. Kramer, Manyalibo J. Matthews, Christopher J. Tassone, Kevin H. Stone

Ames Laboratory Accepted Manuscripts

Laser powder bed fusion (LPBF) is a method of additive manufacturing characterized by the rapid scanning of a high powered laser over a thin bed of metallic powder to create a single layer, which may then be built upon to form larger structures. Much of the melting, resolidification, and subsequent cooling take place at much higher rates and with much higher thermal gradients than in traditional metallurgical processes, with much of this occurring below the surface. We have used in situ high speed X-ray diffraction to extract subsurface cooling rates following resolidification from the melt and above the β-transus ...


Differential Effect Of Magnetic Alignment On Additive Manufacturing Of Magnetocaloric Particles, Karam N. Al-Milaji, Shalabh Gupta, Vitalij K. Pecharsky, Radhika Barua, Hong Zhao, Ravi L. Hadimani Jan 2020

Differential Effect Of Magnetic Alignment On Additive Manufacturing Of Magnetocaloric Particles, Karam N. Al-Milaji, Shalabh Gupta, Vitalij K. Pecharsky, Radhika Barua, Hong Zhao, Ravi L. Hadimani

Ames Laboratory Accepted Manuscripts

Additive manufacturing of materials using magnetic particles as feedstock has attracted tremendous attention during the past decade owing to its ability to tune both shape and magnetocrystalline anisotropy, which can significantly enhance the magnetic characteristics of materials. We demonstrate that the magnetic response of multilayered thin films of Gd5Si4 can be tailored by controlling the external magnetic field during inkjet printing. The external magnetic field aligns the magnetic particles along their magnetic easy axis, enhancing the magnetic anisotropy of the printed films. Our work demonstrates the ability to print thin magnetic films with a defined anisotropy in any chosen direction ...


Computer Vision And Machine Learning Enabled Soybean Root Phenotyping Pipeline, Kevin G. Falk, Talukder Z. Jubery, Seyed V. Mirnezami, Kyle A. Parmley, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian, Asheesh K. Singh Jan 2020

Computer Vision And Machine Learning Enabled Soybean Root Phenotyping Pipeline, Kevin G. Falk, Talukder Z. Jubery, Seyed V. Mirnezami, Kyle A. Parmley, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian, Asheesh K. Singh

Mechanical Engineering Publications

Background Root system architecture (RSA) traits are of interest for breeding selection; however, measurement of these traits is difficult, resource intensive, and results in large variability. The advent of computer vision and machine learning (ML) enabled trait extraction and measurement has renewed interest in utilizing RSA traits for genetic enhancement to develop more robust and resilient crop cultivars. We developed a mobile, low-cost, and high-resolution root phenotyping system composed of an imaging platform with computer vision and ML based segmentation approach to establish a seamless end-to-end pipeline - from obtaining large quantities of root samples through image based trait processing and ...


Heart Valve Isogeometric Sequentially-Coupled Fsi Analysis With The Space–Time Topology Change Method, Takuya Terahara, Kenji Takizawa, Tayfun E. Tezduyar, Yuri Bazilevs, Ming-Chen Hsu Jan 2020

Heart Valve Isogeometric Sequentially-Coupled Fsi Analysis With The Space–Time Topology Change Method, Takuya Terahara, Kenji Takizawa, Tayfun E. Tezduyar, Yuri Bazilevs, Ming-Chen Hsu

Mechanical Engineering Publications

Heart valve fluid–structure interaction (FSI) analysis is one of the computationally challenging cases in cardiovascular fluid mechanics. The challenges include unsteady flow through a complex geometry, solid surfaces with large motion, and contact between the valve leaflets. We introduce here an isogeometric sequentially-coupled FSI (SCFSI) method that can address the challenges with an outcome of high-fidelity flow solutions. The SCFSI analysis enables dealing with the fluid and structure parts individually at different steps of the solutions sequence, and also enables using different methods or different mesh resolution levels at different steps. In the isogeometric SCFSI analysis here, the first ...


Recovery Of Encapsulated Adult Neural Progenitor Cells From Microfluidic-Spun Hydrogel Fibers Enhances Proliferation And Neuronal Differentiation, Bhavika B. Patel, Marilyn C. Mcnamara, Laura S. Pesquera-Colom, Emily M. Kozik, Jasmin Okuzonu, Nicole N. Hashemi, Donald S. Sakaguchi Jan 2020

Recovery Of Encapsulated Adult Neural Progenitor Cells From Microfluidic-Spun Hydrogel Fibers Enhances Proliferation And Neuronal Differentiation, Bhavika B. Patel, Marilyn C. Mcnamara, Laura S. Pesquera-Colom, Emily M. Kozik, Jasmin Okuzonu, Nicole N. Hashemi, Donald S. Sakaguchi

Genetics, Development and Cell Biology Publications

Because of the limitations imposed by traditional two-dimensional (2D) cultures, biomaterials have become a major focus in neural and tissue engineering to study cell behavior in vitro. 2D systems fail to account for interactions between cells and the surrounding environment; these cell–matrix interactions are important to guide cell differentiation and influence cell behavior such as adhesion and migration. Biomaterials provide a unique approach to help mimic the native microenvironment in vivo. In this study, a novel microfluidic technique is used to encapsulate adult rat hippocampal stem/progenitor cells (AHPCs) within alginate-based fibrous hydrogels. To our knowledge, this is the ...


The Impact Of Biochar Treatment On H2s And Nh3 Emissions During Manure Agitation Prior To Pump-Out, Baitong Chen, Jacek A. Koziel, Myeongseong Lee, Hantian Ma, Zhanibek Meiirkhanuly, Peiyang Li, Andrzej Białowiec, Robert C. Brown Jan 2020

The Impact Of Biochar Treatment On H2s And Nh3 Emissions During Manure Agitation Prior To Pump-Out, Baitong Chen, Jacek A. Koziel, Myeongseong Lee, Hantian Ma, Zhanibek Meiirkhanuly, Peiyang Li, Andrzej Białowiec, Robert C. Brown

Agricultural and Biosystems Engineering Conference Proceedings and Presentations

Hydrogen sulfide and ammonia are always a concern in the livestock industries, especially when farmers try to clear their manure storage pits. Agitation of manure can cause dangerously high concentrations of harmful agents such as H2S and NH3 to be emitted into the air. Biochar can absorb these gases. We hypothesized that applying biochar on top of manure can create an effective barrier to protect farmers and animals from exposure to NH3 and H2S. In this study, one kind of biochar was tested, highly alkaline, and porous (HAP, pH 9.2) biochar made from ...


An Exact Formulation For Exponential-Logarithmic Transformation Stretches In A Multiphase Phase Field Approach To Martensitic Transformations, Anup Basak, Valery I. Levitas Jan 2020

An Exact Formulation For Exponential-Logarithmic Transformation Stretches In A Multiphase Phase Field Approach To Martensitic Transformations, Anup Basak, Valery I. Levitas

Aerospace Engineering Publications

A general theoretical and computational procedure for dealing with an exponential-logarithmic kinematic model for transformation stretch tensor in a multiphase phase field approach to stress- and temperature- induced martensitic transformations with N martensitic variants is developed for transformations between all possible crystal lattices. This kinematic model, where the natural logarithm of transformation stretch tensor is a linear combination of natural logarithm of the Bain tensors, yields isochoric variant-variant transformations for the entire transformation path. Such a condition is plausible and cannot be satisfied by the widely used kinematic model where the transformation stretch tensor is linear in Bain tensors. Earlier ...


Nurbs-Based Microstructure Design For Organic Photovoltaics, Ramin Noruzi, Sambit Ghadai, Onur Rauf Bingol, Adarsh Krishnamurthy, Baskar Ganapathysubramanian Jan 2020

Nurbs-Based Microstructure Design For Organic Photovoltaics, Ramin Noruzi, Sambit Ghadai, Onur Rauf Bingol, Adarsh Krishnamurthy, Baskar Ganapathysubramanian

Mechanical Engineering Publications

The microstructure – spatial distribution of electron donor and acceptor domains – plays an important role in determining the photo current in thin film organic solar cells (OSCs). Optimizing the microstructure can lead to higher photo current generation, and is an active area of experimental research. There has been recent progress in framing OSC microstructure design as a computational design problem. However, most current approaches to microstructure optimization are based on volumetric distribution of material, which makes the design space very large. In contrast, we frame the microstructure design optimization problem in terms of designing the interface between the donor and acceptor ...


Usefulness Of Interpretability Methods To Explain Deep Learning Based Plant Stress Phenotyping, Koushik Nagasubramanian, Asheesh K. Singh, Arti Singh, Soumik Sarkar, Baskar Ganapathysubramanian Jan 2020

Usefulness Of Interpretability Methods To Explain Deep Learning Based Plant Stress Phenotyping, Koushik Nagasubramanian, Asheesh K. Singh, Arti Singh, Soumik Sarkar, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Deep learning techniques have been successfully deployed for automating plant stress identification and quantification. In recent years, there is a growing push towards training models that are interpretable -i.e. that justify their classification decisions by visually highlighting image features that were crucial for classification decisions. The expectation is that trained network models utilize image features that mimic visual cues used by plant pathologists. In this work, we compare some of the most popular interpretability methods: Saliency Maps, SmoothGrad, Guided Backpropogation, Deep Taylor Decomposition, Integrated Gradients, Layer-wise Relevance Propagation and Gradient times Input, for interpreting the deep learning model. We ...


Tetrahydrofuran-Based Two-Step Solvent Liquefaction Process For Production Of Lignocellulosic Sugars, Arpa Ghosh, Martin R. Haverly, Jake K. Lindstrom, Patrick A. Johnston, Robert C. Brown Jan 2020

Tetrahydrofuran-Based Two-Step Solvent Liquefaction Process For Production Of Lignocellulosic Sugars, Arpa Ghosh, Martin R. Haverly, Jake K. Lindstrom, Patrick A. Johnston, Robert C. Brown

Mechanical Engineering Publications

Large-scale production of biofuels and chemicals will require cost-effective, sustainable, and rapid deconstruction of waste biomass into its constituent sugars. Here, we introduce a novel two-step liquefaction process for producing fermentable sugars from hardwood biomass using a mixture of tetrahydrofuran (THF), water and dilute sulfuric acid. THF promotes acid-catalyzed solubilization of lignin and hemicellulose in biomass achieving 61% lignin extraction and 64% xylose recovery in a mild pretreatment step. The pretreatment opens the structure of biomass through delignification and produces a cellulose-rich biomass, which is readily solubilized at low temperature giving 65% total sugar yields in a subsequent liquefaction process ...