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Mechanical Engineering Publications

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Full-Text Articles in Mechanical Engineering

Viscoelastic Properties Of Shock Wave Exposed Brain Tissue Subjected To Unconfined Compression Experiments, Annastacia K. Mccarty, Ling Zhang, Sarah Hansen, William J. Jackson, Sarah A. Bentil Dec 2019

Viscoelastic Properties Of Shock Wave Exposed Brain Tissue Subjected To Unconfined Compression Experiments, Annastacia K. Mccarty, Ling Zhang, Sarah Hansen, William J. Jackson, Sarah A. Bentil

Mechanical Engineering Publications

Traumatic brain injuries (TBI) affect millions of people each year. While research has been dedicated to determining the mechanical properties of the uninjured brain, there has been a lack of investigation on the mechanical properties of the brain after experiencing a primary blast-induced TBI. In this paper, whole porcine brains were exposed to a shock wave to simulate blast-induced TBI. First, ten (10) brains were subjected to unconfined compression experiments immediately following shock wave exposure. In addition, 22 brains exposed to a shock wave were placed in saline solution and refrigerated between 30 minutes and 6.0 hours before undergoing ...


Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian Aug 2019

Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Background

Hyperspectral imaging is emerging as a promising approach for plant disease identification. The large and possibly redundant information contained in hyperspectral data cubes makes deep learning based identification of plant diseases a natural fit. Here, we deploy a novel 3D deep convolutional neural network (DCNN) that directly assimilates the hyperspectral data. Furthermore, we interrogate the learnt model to produce physiologically meaningful explanations. We focus on an economically important disease, charcoal rot, which is a soil borne fungal disease that affects the yield of soybean crops worldwide.

Results

Based on hyperspectral imaging of inoculated and mock-inoculated stem images, our 3D ...


Stamped Multilayer Graphene Laminates For Disposable In-Field Electrodes: Application To Electrochemical Sensing Of Hydrogen Peroxide And Glucose, Loreen R. Stromberg, John A. Hondred, Delaney Sanborn, Deyny Mendivelso-Perez, Srikanthan Ramesh, Iris V. Rivero, Josh Kogot, Emily Smith, Carmen Gomes, Jonathan C. Claussen Aug 2019

Stamped Multilayer Graphene Laminates For Disposable In-Field Electrodes: Application To Electrochemical Sensing Of Hydrogen Peroxide And Glucose, Loreen R. Stromberg, John A. Hondred, Delaney Sanborn, Deyny Mendivelso-Perez, Srikanthan Ramesh, Iris V. Rivero, Josh Kogot, Emily Smith, Carmen Gomes, Jonathan C. Claussen

Mechanical Engineering Publications

A multi-step approach is described for the fabrication of multi-layer graphene-based electrodes without the need for ink binders or post-print annealing. Graphite and nanoplatelet graphene were chemically exfoliated using a modified Hummers’ method and the dried material was thermally expanded. Expanded materials were used in a 3D printed mold and stamp to create laminate electrodes on various substrates. The laminates were examined for potential sensing applications using model systems of peroxide (H2O2) and enzymatic glucose detection. Within the context of these two assay systems, platinum nanoparticle electrodeposition and oxygen plasma treatment were examined as methods for improving sensitivity. Electrodes made ...


Development Of Optimized Phenomic Predictors For Efficient Plant Breeding Decisions Using Phenomic-Assisted Selection In Soybean, Kyle Parmley, Koushik Nagasubramanian, Soumik Sarkar, Baskar Ganapathysubramanian, Asheesh K. Singh Jul 2019

Development Of Optimized Phenomic Predictors For Efficient Plant Breeding Decisions Using Phenomic-Assisted Selection In Soybean, Kyle Parmley, Koushik Nagasubramanian, Soumik Sarkar, Baskar Ganapathysubramanian, Asheesh K. Singh

Mechanical Engineering Publications

The rate of advancement made in phenomic-assisted breeding methodologies has lagged those of genomic-assisted techniques, which is now a critical component of mainstream cultivar development pipelines. However, advancements made in phenotyping technologies have empowered plant scientists with affordable high-dimensional datasets to optimize the operational efficiencies of breeding programs. Phenomic and seed yield data was collected across six environments for a panel of 292 soybean accessions with varying genetic improvements. Random forest, a machine learning (ML) algorithm, was used to map complex relationships between phenomic traits and seed yield and prediction performance assessed using two cross-validation (CV) scenarios consistent with breeding ...


Immersogeometric Analysis Of Moving Objects In Incompressible Flows, Songzhe Xu, Fei Xu, Aditya Kommajosula, Ming-Chen Hsu, Baskar Ganapathysubramanian Jul 2019

Immersogeometric Analysis Of Moving Objects In Incompressible Flows, Songzhe Xu, Fei Xu, Aditya Kommajosula, Ming-Chen Hsu, Baskar Ganapathysubramanian

Mechanical Engineering Publications

We deploy the immersogeometric approach for tracking moving objects. The method immerses objects into non-boundary-fitted meshes and weakly enforces Dirichlet boundary conditions on the object boundaries. The object motion is driven by the integrated surface force and external body forces. A residual-based variational multiscale method is employed to stabilize the finite element formulation for incompressible flows. Adaptively refined quadrature rules are used to better capture the geometry of the immersed boundaries by accurately integrating the intersected background elements. Treatment for the freshly-cleared nodes (i.e. background mesh nodes that are inside the object at one time step, but are in ...


Porous Wood Monoliths Decorated With Platinum Nano-Urchins As Catalysts For Underwater Micro-Vehicle Propulsion Via H2o2 Decomposition, Bolin Chen, Ahmed Gsalla, Anand Gaur, Yu Hui Lui, Xiaohui Tang, Jason Geder, Marius Pruessner, Brian J. Melde, Igor L. Medintz, Behrouz Shafei, Shan Hu, Jonathan C. Claussen Jun 2019

Porous Wood Monoliths Decorated With Platinum Nano-Urchins As Catalysts For Underwater Micro-Vehicle Propulsion Via H2o2 Decomposition, Bolin Chen, Ahmed Gsalla, Anand Gaur, Yu Hui Lui, Xiaohui Tang, Jason Geder, Marius Pruessner, Brian J. Melde, Igor L. Medintz, Behrouz Shafei, Shan Hu, Jonathan C. Claussen

Mechanical Engineering Publications

Porous carbon is becoming an important and promising high-surface area scaffold material for various energy-based applications including catalysis. Here we demonstrate the growth of urchin-like platinum nanoparticles (PtNPs) on carbon monoliths derived from basswood that work as catalysts for micro underwater vehicle (MUV) propulsion via H2O2 decomposition. The carbon monoliths were constructed of natural basswood that was carbonized in argon (Ar) and subjected to a subsequent CO2 activation process that rendered the material into a hardened 3D porous activated carbonized wood (ACW) with inner channel voids measuring 10-70 μm in diameter. The PtNP nanourchins (500 nm or less in total ...


Dropwise Condensation On Multi-Scale Bioinspired Metallic Surfaces With Nano-Features, Daniel Orejon, Alexandros Askounis, Yasuyuki Takata, Daniel Attinger Jun 2019

Dropwise Condensation On Multi-Scale Bioinspired Metallic Surfaces With Nano-Features, Daniel Orejon, Alexandros Askounis, Yasuyuki Takata, Daniel Attinger

Mechanical Engineering Publications

Non-wetting surfaces engineered from intrinsically hydrophilic metallic materials are promising for self-cleaning, anti-icing and/or condensation heat transfer applications where the durability of the coating is an issue. In this work, we fabricate and study the wetting behaviour and the condensation performance on two metallic non-wetting surfaces with varying number and size of the roughness tiers without further hydrophobic coating procedure. On one hand, the surface resembling a rose petal exhibits a sticky non-wetting behaviour as drops wet the microscopic roughness features with the consequent enhanced drop adhesion, which leads to filmwise condensation. On the other hand, the surface resembling ...


Encoding Invariances In Deep Generative Models, Viraj Shah, Ameya Joshi, Sambuddha Ghosal, Balaji Pokuri, Soumik Sarkar, Baskar Ganapathysubramanian, Chinmay Hegde Jun 2019

Encoding Invariances In Deep Generative Models, Viraj Shah, Ameya Joshi, Sambuddha Ghosal, Balaji Pokuri, Soumik Sarkar, Baskar Ganapathysubramanian, Chinmay Hegde

Mechanical Engineering Publications

Reliable training of generative adversarial networks (GANs) typically require massive datasets in order to model complicated distributions. However, in several applications, training samples obey invariances that are \textit{a priori} known; for example, in complex physics simulations, the training data obey universal laws encoded as well-defined mathematical equations. In this paper, we propose a new generative modeling approach, InvNet, that can efficiently model data spaces with known invariances. We devise an adversarial training algorithm to encode them into data distribution. We validate our framework in three experimental settings: generating images with fixed motifs; solving nonlinear partial differential equations (PDEs); and ...


Computational Cardiovascular Flow Analysis With The Variational Multiscale Methods, Kenji Takizawa, Yuri Bazilevs, Tayfun E. Tezduyar, Ming-Chen Hsu Jun 2019

Computational Cardiovascular Flow Analysis With The Variational Multiscale Methods, Kenji Takizawa, Yuri Bazilevs, Tayfun E. Tezduyar, Ming-Chen Hsu

Mechanical Engineering Publications

Computational cardiovascular flow analysis can provide valuable information to medical doctors in a wide range of patientspecific cases, including cerebral aneurysms, aortas and heart valves. The computational challenges faced in this class of flow analyses also have a wide range. They include unsteady flows, complex cardiovascular geometries, moving boundaries and interfaces, such as the motion of the heart valve leaflets, contact between moving solid surfaces, such as the contact between the leaflets, and the fluid–structure interaction between the blood and the cardiovascular structure. Many of these challenges have been or are being addressed by the Space–Time Variational Multiscale ...


Utilization Of Reduced Haploid Vigor For Phenomic Discrimination Of Haploid And Diploid Maize Seedlings, Kimberly Vanous, Talukder Jubery, Ursula K. Frei, Baskar Ganapathysubramanian, Thomas Lubberstedt Apr 2019

Utilization Of Reduced Haploid Vigor For Phenomic Discrimination Of Haploid And Diploid Maize Seedlings, Kimberly Vanous, Talukder Jubery, Ursula K. Frei, Baskar Ganapathysubramanian, Thomas Lubberstedt

Mechanical Engineering Publications

Potential benefits of incorporating embryo culture (EC) into a doubled haploid (DH) program, including shortening the breeding cycle and increasing chromosome doubling rates, make the laborious and tedious task of excising embryos worth the effort. Difficulties arise during embryo selection considering the marker gene R1-nj, which is typically used in DH programs, is not expressed in early stages after pollination. Although transgenic approaches have been implemented to bypass this issue, there is so far no known non-transgenic method of selecting haploid embryos. The findings of this study reveal methods of selecting haploid embryos that allow the possibility of incorporating EC ...


Placenta‐On‐A‐Chip: In Vitro Study Of Caffeine Transport Across Placental Barrier Using Liquid Chromatography Mass Spectrometry, Rajeendra L. Pemathilaka, Jeremy D. Caplin, Saurabh S. Aykar, Reza Montazami, Nicole N. Hashemi Mar 2019

Placenta‐On‐A‐Chip: In Vitro Study Of Caffeine Transport Across Placental Barrier Using Liquid Chromatography Mass Spectrometry, Rajeendra L. Pemathilaka, Jeremy D. Caplin, Saurabh S. Aykar, Reza Montazami, Nicole N. Hashemi

Mechanical Engineering Publications

Due to the particular structure and functionality of the placenta, most current human placenta drug testing methods are limited to animal models, conventional cell testing, and cohort/controlled testing. Previous studies have produced inconsistent results due to physiological differences between humans and animals and limited availability of human and/or animal models for controlled testing. To overcome these challenges, a placenta‐on‐a‐chip system is developed for studying the exchange of substances to and from the placenta. Caffeine transport across the placental barrier is studied because caffeine is a xenobiotic widely consumed on a daily basis. Since a fetus ...


Binary 2d Morphologies Of Polymer Phase Separation: Dataset And Python Toolbox, Viraj Shah, Ameya Joshi, Balaji Sesha Sarath Pokuri, Sambuddha Ghosal, Soumik Sarkar, Baskar Ganapathysubramanian, Chinmay Hegde Mar 2019

Binary 2d Morphologies Of Polymer Phase Separation: Dataset And Python Toolbox, Viraj Shah, Ameya Joshi, Balaji Sesha Sarath Pokuri, Sambuddha Ghosal, Soumik Sarkar, Baskar Ganapathysubramanian, Chinmay Hegde

Mechanical Engineering Publications

Study of the intricate connection between the design of material distributions (also called morphology or microstructure) and the final properties of the material system has been an attractive research theme for material science community. Such analysis provides ability to synthesize the microstructures exhibiting desired properties. This theme encompasses several material systems including porous materials [26], steels and welds [2], composites [14], powder metallurgy [28], 3D printing [22], energy storage devices as batteries [10], and energy converting devices like bulk hetero-junction solar cells [20]. Microstructure-sensitive design has been used to tailor a wide variety of properties including strengths, heat and mass ...


Pre-Methylation Of Lignin To Improve Storage Stability Of Oil Produced By Solvent Liquefaction, Jae-Young Kim, Parinaz Hafezi-Sefat, Sarah D. Cady, Ryan G. Smith, Robert C. Brown Jan 2019

Pre-Methylation Of Lignin To Improve Storage Stability Of Oil Produced By Solvent Liquefaction, Jae-Young Kim, Parinaz Hafezi-Sefat, Sarah D. Cady, Ryan G. Smith, Robert C. Brown

Mechanical Engineering Publications

In this study, we methylated hydroxyl groups (phenolic hydroxyl: Phe-OH and aliphatic hydroxyl: Aliph-OH) in soda lignin (SL) prior to solvent liquefaction to improve storage stability of the resulting oil. We investigated two methylating reagents, dimethyl sulfate (DMS) and dimethyl carbonate (DMC), for selective Phe-OH and total hydroxyl group (Phe-OH and Aliph-OH) blocking. Samples of SL, DMS-SL, and DMC-SL were depolymerized into oils under supercritical ethanol (350 °C). Both methylated lignins produced higher amounts of oils and smaller amounts of char compared to untreated SL due to suppressed charring reactions. Oil produced from SL had relatively higher functional group contents ...


High Throughput, Automated Prediction Of Focusing Patterns For Inertial Microfluidics, Aditya Kommajosula, Jeong-Ah Kim, Wonhee Lee, Baskar Ganapathysubramanian Jan 2019

High Throughput, Automated Prediction Of Focusing Patterns For Inertial Microfluidics, Aditya Kommajosula, Jeong-Ah Kim, Wonhee Lee, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Visual inspections for identifying focusing points in inertial microfluidic flows are prone to misinterpreting stable locations and focusing shifts in the case of non-trivial focusing patterns. We develop and deploy an approach for automating the calculation of focusing patterns for a general channel geometry, and thereby reduce the dependence on empirical/visual procedures to confirm the presence of stable locations. We utilize concepts from interpolation theory (to represent continuous force-fields using discrete points), and stability theory to identify "basins of attraction" and quantitatively identify stable equilibrium points. Our computational experiments reveal that predicting equilibrium points accurately requires upto ×10-20 times ...


Enhanced Electrochemical Biosensor And Supercapacitor With 3d Porous Architectured Graphene Via Salt Impregnated Inkjet Maskless Lithography, John A. Hondred, Igor L. Medintz, Jonathan C. Claussen Jan 2019

Enhanced Electrochemical Biosensor And Supercapacitor With 3d Porous Architectured Graphene Via Salt Impregnated Inkjet Maskless Lithography, John A. Hondred, Igor L. Medintz, Jonathan C. Claussen

Mechanical Engineering Publications

Advances in solution-phase graphene patterning has provided a facile route for rapid, low-cost and scalable manufacturing of electrochemical devices, even on flexible substrates. While graphene possesses advantageous electrochemical properties of high surface area and fast heterogenous charge transport, these properties are attributed to the edge planes and defect sites, not the basal plane. Herein, we demonstrate enhancement of the electroactive nature of patterned solution-phase graphene by increasing the porosity and edge planes through the construction of a multidimensional architecture via salt impregnated inkjet maskless lithography (SIIML) and CO2 laser annealing. Various sized macroscale pores (<25 to ∼250 μm) are patterned directly in the graphene surface by incorporating porogens (i.e., salt crystals) in the ...


Shape-Design For Stabilizing Micro-Particles In Inertial Microfluidic Flows, Aditya Kommajosula, Daniel Stoecklein, Dino Di Carlo, Baskar Ganapathysubramanian Jan 2019

Shape-Design For Stabilizing Micro-Particles In Inertial Microfluidic Flows, Aditya Kommajosula, Daniel Stoecklein, Dino Di Carlo, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Design of microparticles which stabilize at the centerline of a channel flow when part of a dilute suspension is examined numerically for moderate Reynolds numbers (10≤Re≤80). Stability metrics for particles with arbitrary shapes are formulated based on linear-stability theory. Particle shape is parametrized by a compact, Non-Uniform Rational B-Spline (NURBS)-based representation. Shape-design is posed as an optimization problem and solved using adaptive Bayesian optimization. We focus on designing particles for maximal stability at the channel-centerline robust to perturbations. Our results indicate that centerline-focusing particles are families of characteristic "fish"/"bottle"/"dumbbell"-like shapes, exhibiting fore-aft asymmetry. A ...


In Silico Design Of Crop Ideotypes Under A Wide Range Of Water Availability, Talukder Z. Jubery, Baskar Ganapathysubramanian, Matthew E. Gilbert, Daniel Attinger Jan 2019

In Silico Design Of Crop Ideotypes Under A Wide Range Of Water Availability, Talukder Z. Jubery, Baskar Ganapathysubramanian, Matthew E. Gilbert, Daniel Attinger

Mechanical Engineering Publications

Given the changing climate and increasing impact of agriculture on global resources, it is important to identify phenotypes which are global and sustainable optima. Here, an in silico framework is constructed by coupling evolutionary optimization with thermodynamically sound crop physiology, and its ability to rationally design phenotypes with maximum productivity is demonstrated, within well‐defined limits on water availability. Results reveal that in mesic environments, such as the North American Midwest, and semi‐arid environments, such as Colorado, phenotypes optimized for maximum productivity and survival under drought are similar to those with maximum productivity under irrigated conditions. In hot and ...


Efficient Solar-To-Thermal Energy Conversion And Storage With High-Thermal-Conductivity And Form-Stabilized Phase Change Composite Based On Wood-Derived Scaffolds, Bolin Chen, Meng Han, Bowei Zhang, Gaoyuan Ouyang, Behrouz Shafei, Xinwei Wang, Shan Hu Jan 2019

Efficient Solar-To-Thermal Energy Conversion And Storage With High-Thermal-Conductivity And Form-Stabilized Phase Change Composite Based On Wood-Derived Scaffolds, Bolin Chen, Meng Han, Bowei Zhang, Gaoyuan Ouyang, Behrouz Shafei, Xinwei Wang, Shan Hu

Mechanical Engineering Publications

Solar-to-thermal energy conversion is one of the most efficient ways to harvest solar energy. In this study, a novel phase change composite with porous carbon monolith derived from natural wood is fabricated to harvest solar irradiation and store it as thermal energy. Organic phase change material n-octadecane is physically adsorbed inside the porous structure of the carbonized wood, and a thin graphite coating encapsulates the exterior of the wood structure to further prevent n-octadecane leakage. The carbonized wood scaffold and the graphite coating not only stabilize the form of the n-octadecane during phase change, but also enhance its thermal conductivity ...


A Data Set Of Bloodstain Patterns For Teaching And Research In Bloodstain Pattern Analysis: Gunshot Backspatters, Daniel Attinger, Yu Liu, Ricky Faflak, Yalin Rao, Bryce A. Struttman, Kris De Brabanter, Patrick M. Comiskey, Alex L. Yarin Nov 2018

A Data Set Of Bloodstain Patterns For Teaching And Research In Bloodstain Pattern Analysis: Gunshot Backspatters, Daniel Attinger, Yu Liu, Ricky Faflak, Yalin Rao, Bryce A. Struttman, Kris De Brabanter, Patrick M. Comiskey, Alex L. Yarin

Mechanical Engineering Publications

This is a data set of blood spatter patterns scanned at high resolution, generated in controlled experiments. The spatter patterns were generated with a rifle or a handgun, and different ammunitions. The resulting atomized blood droplets travelled opposite to the bullet direction, generating a gunshot backspatter on a poster board target sheet. Fresh blood with anticoagulants was used; its hematocrit and temperature were measured. Main parameters of the study were the bullet shape, size and speed, and the distance between the blood source and target sheet. Several other parameters were explored in a less systematic way. This new and original ...


Flexible Laser-Induced Graphene For Nitrogen Sensing In Soil, Nate T. Garland, Eric S. Mclamore, Nicholas D. Cavallaro, Deyny Mendivelso-Perez, Emily A. Smith, Dapeng Jing, Jonathan C. Claussen Nov 2018

Flexible Laser-Induced Graphene For Nitrogen Sensing In Soil, Nate T. Garland, Eric S. Mclamore, Nicholas D. Cavallaro, Deyny Mendivelso-Perez, Emily A. Smith, Dapeng Jing, Jonathan C. Claussen

Mechanical Engineering Publications

Flexible graphene electronics are rapidly gaining interest, but their widespread implementation has been impeded by challenges with ink preparation, ink printing, and post-print annealing processes. Laser-induced graphene (LIG) promises a facile alternative by creating flexible graphene electronics on polyimide substrates through a one-step laser writing fabrication method. Herein we demonstrate the use of LIG, created through a low-cost UV laser, for electrochemical ion selective sensing of plant-available nitrogen (i.e., both ammonium and nitrate ions: NH4+ and NO3-) in soil samples. The laser used to create the LIG was operated at distinct pulse rates (10, 20, 30, 40, and 50 ...


Lanthanide Ions Doped In Vanadium Oxide For Sensitive Optical Glucose Detection, Ansam J. Talib, Masfer Alkahtani, Linkun Jiang, Fahad Alghannam, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Alexei V. Sokolov, Philip R. Hemmer Nov 2018

Lanthanide Ions Doped In Vanadium Oxide For Sensitive Optical Glucose Detection, Ansam J. Talib, Masfer Alkahtani, Linkun Jiang, Fahad Alghannam, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Alexei V. Sokolov, Philip R. Hemmer

Mechanical Engineering Publications

Blood glucose monitoring is essential to avoid the unwanted consequences of glucose level fluctuations. Optical monitors are of special interest because they can be non-invasive. Among optical glucose sensors, fluorescent upconversion nanoparticles (UCNPs) have the advantage of good photostability, low toxicity, and exceptional autofluorescence suppression. However, to sense glucose, UCNPs normally need surface functionalization, and this can be easily affected by other factors in biological systems, and may also affect their ability for real-time sensing of both increasing and decreasing glucose levels. Here, we report YVO4 : Yb3+, Er3+@Nd3+core/shell UCNPs with Nd and Yb shell and GdVO4 : Yb3 ...


A Novel Multirobot System For Plant Phenotyping, Tianshuang Gao, Hamid Emadi, Homagni Saha, Jiaoping Zhang, Alec Lofquist, Arti Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Asheesh K. Singh, Sourabh Bhattacharya Sep 2018

A Novel Multirobot System For Plant Phenotyping, Tianshuang Gao, Hamid Emadi, Homagni Saha, Jiaoping Zhang, Alec Lofquist, Arti Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Asheesh K. Singh, Sourabh Bhattacharya

Mechanical Engineering Publications

Phenotypic studies require large datasets for accurate inference and prediction. Collecting plant data in a farm can be very labor intensive and costly. This paper presents the design, architecture (hardware and software) and deployment of a multi-robot system for row crop field data collection. The proposed system has been deployed in a soybean research farm at Iowa State University.


Microstructure Design Using Graphs, Pengfei Du, Adrian Zebrowski, Jaroslaw Zola, Baskar Ganapathysubramanian, Olga Wodo Sep 2018

Microstructure Design Using Graphs, Pengfei Du, Adrian Zebrowski, Jaroslaw Zola, Baskar Ganapathysubramanian, Olga Wodo

Mechanical Engineering Publications

Thin films with tailored microstructures are an emerging class of materials with applications such as battery electrodes, organic electronics, and biosensors. Such thin film devices typically exhibit a multi-phase microstructure that is confined, and show large anisotropy. Current approaches to microstructure design focus on optimizing bulk properties, by tuning features that are statistically averaged over a representative volume. Here, we report a tool for morphogenesis posed as a graph-based optimization problem that evolves microstructures recognizing confinement and anisotropy constraints. We illustrate the approach by designing optimized morphologies for photovoltaic applications, and evolve an initial morphology into an optimized morphology exhibiting ...


Shaped 3d Microcarriers For Adherent Cell Culture And Analysis, Chueh-Yu Wu, Daniel Stoecklein, Aditya Kommajosula, Jonathan Lin, Keegan Owsley, Baskar Ganapathysubramanian, Dino Di Carlo Aug 2018

Shaped 3d Microcarriers For Adherent Cell Culture And Analysis, Chueh-Yu Wu, Daniel Stoecklein, Aditya Kommajosula, Jonathan Lin, Keegan Owsley, Baskar Ganapathysubramanian, Dino Di Carlo

Mechanical Engineering Publications

Standard tissue culture of adherent cells is known to poorly replicate physiology and often entails suspending cells in solution for analysis and sorting, which modulates protein expression and eliminates intercellular connections. To allow adherent culture and processing in flow, we present 3D-shaped hydrogel cell microcarriers, which are designed with a recessed nook in a first dimension to provide a tunable shear-stress shelter for cell growth, and a dumbbell shape in an orthogonal direction to allow for self-alignment in a confined flow, important for processing in flow and imaging flow cytometry. We designed a method to rapidly design, using the genetic ...


Error Estimates For Projection-Based Dynamic Augmented Lagrangian Boundary Condition Enforcement, With Application To Fluid–Structure Interaction, Yue Yu, David Kamensky, Ming-Chen Hsu, Xin Yang Lu, Yuri Bazilevs, Thomas J.R. Hughes Aug 2018

Error Estimates For Projection-Based Dynamic Augmented Lagrangian Boundary Condition Enforcement, With Application To Fluid–Structure Interaction, Yue Yu, David Kamensky, Ming-Chen Hsu, Xin Yang Lu, Yuri Bazilevs, Thomas J.R. Hughes

Mechanical Engineering Publications

In this work, we analyze the convergence of the recent numerical method for enforcing fluid–structure interaction (FSI) kinematic constraints in the immersogeometric framework for cardiovascular FSI. In the immersogeometric framework, the structure is modeled as a thin shell, and its influence on the fluid subproblem is imposed as a forcing term. This force has the interpretation of a Lagrange multiplier field supplemented by penalty forces, in an augmented Lagrangian formulation of the FSI kinematic constraints. Because of the non-matching fluid and structure discretizations used, no discrete inf-sup condition can be assumed. To avoid solving (potentially unstable) discrete saddle point ...


Electrochemical Glucose Sensors Enhanced By Methyl Viologen And Vertically Aligned Carbon Nanotube Channels, Benjamin J. Brownlee, Meisam Bahari, John N. Harb, Jonathan C. Claussen, Brian D. Iverson Aug 2018

Electrochemical Glucose Sensors Enhanced By Methyl Viologen And Vertically Aligned Carbon Nanotube Channels, Benjamin J. Brownlee, Meisam Bahari, John N. Harb, Jonathan C. Claussen, Brian D. Iverson

Mechanical Engineering Publications

Free-standing, vertically aligned carbon nanotubes (VACNTs) were patterned into 16 µm diameter microchannel arrays for flow-through electrochemical glucose sensing. Non-enzymatic sensing of glucose was achieved by the chemical reaction of glucose with methyl viologen (MV) at an elevated temperature and pH (0.1 M NaOH), followed by the electrochemical reaction of reduced-MV with the VACNT surface. The MV sensor required no functionalization (including no metal) and was able to produce on average 3.4 electrons per glucose molecule. The current density of the MV sensor was linear with both flow rate and glucose concentration. Challenges with interference chemicals were mitigated ...


A Novel Multirobot System For Distributed Phenotyping, Tianshuang Gao, Homagni Saha, Hamid Emadi, Jiaoping Zhang, Alec Lofquist, Arti Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Asheesh Singh, Sourabh Bhattacharya Jul 2018

A Novel Multirobot System For Distributed Phenotyping, Tianshuang Gao, Homagni Saha, Hamid Emadi, Jiaoping Zhang, Alec Lofquist, Arti Singh, Baskar Ganapathysubramanian, Soumik Sarkar, Asheesh Singh, Sourabh Bhattacharya

Mechanical Engineering Publications

Phenotypic studies require large datasets for accurate inference and prediction. Collecting plant data in a farm can be very labor intensive and costly. This paper presents the design, architecture (hardware and software) and deployment of a distributed modular agricultural multi-robot system for row crop field data collection. The proposed system has been deployed in a soybean research farm at Iowa State University.


Crowdsourcing Image Analysis For Plant Phenomics To Generate Ground Truth Data For Machine Learning, Naihui Zhou, Zachary D. Siegel, Scott Zarecor, Nigel Lee, Darwin A. Campbell, Carson M. Andorf, Dan Nettleton, Carolyn J. Lawrence-Dill, Baskar Ganapathysubramanian, Jonathan W. Kelly, Iddo Friedberg Jul 2018

Crowdsourcing Image Analysis For Plant Phenomics To Generate Ground Truth Data For Machine Learning, Naihui Zhou, Zachary D. Siegel, Scott Zarecor, Nigel Lee, Darwin A. Campbell, Carson M. Andorf, Dan Nettleton, Carolyn J. Lawrence-Dill, Baskar Ganapathysubramanian, Jonathan W. Kelly, Iddo Friedberg

Mechanical Engineering Publications

The accuracy of machine learning tasks critically depends on high quality ground truth data. Therefore, in many cases, producing good ground truth data typically involves trained professionals; however, this can be costly in time, effort, and money. Here we explore the use of crowdsourcing to generate a large number of training data of good quality. We explore an image analysis task involving the segmentation of corn tassels from images taken in a field setting. We investigate the accuracy, speed and other quality metrics when this task is performed by students for academic credit, Amazon MTurk workers, and Master Amazon MTurk ...


Fluorescent Nanodiamonds: Past, Present, And Future, Masfer H. Alkahtani, Fahad Alghannam, Linkun Jiang, Abdulrahman Almethen, Arfaan A. Rampersaud, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Philip R. Hemmer Jul 2018

Fluorescent Nanodiamonds: Past, Present, And Future, Masfer H. Alkahtani, Fahad Alghannam, Linkun Jiang, Abdulrahman Almethen, Arfaan A. Rampersaud, Robert Brick, Carmen L. Gomes, Marlan O. Scully, Philip R. Hemmer

Mechanical Engineering Publications

Multi-color fluorescent nanodiamonds (FNDs) containing a variety of color centers are promising fluorescent markers for biomedical applications. Compared to colloidal quantum dots and organic dyes, FNDs have the advantage of lower toxicity, exceptional chemical stability, and better photostability. They can be surface functionalized by techniques similar to those used for other nanoparticles. They exhibit a variety of emission wavelengths from visible to near infrared, with narrow or broad bandwidths depending on their color centers. In addition, some color centers can detect changes in magnetic fields, electric fields, and temperature. In this article review, we will discuss the current trends in ...


Synthesis Of Graphene Nanosheets Through Spontaneous Sodiation Process, Deepak-George Thomas, Emrah Kavak, Niloofar Hashemi, Reza Montazami, Nicole N. Hashemi Jul 2018

Synthesis Of Graphene Nanosheets Through Spontaneous Sodiation Process, Deepak-George Thomas, Emrah Kavak, Niloofar Hashemi, Reza Montazami, Nicole N. Hashemi

Mechanical Engineering Publications

Graphene is one of the emerging materials in the nanotechnology industry due to its potential applications in diverse areas. We report the fabrication of graphene nanosheets by spontaneous electrochemical reaction using solvated ion intercalation into graphite. The current literature focuses on the fabrication of graphene using lithium metal. Our procedure uses sodium metal, which results in a reduction of costs. Using various characterization techniques, we confirmed the fabrication of graphene nanosheets. We obtained an intensity ratio (ID/IG) of 0.32 using Raman spectroscopy, interlayer spacing of 0.39 nm and our XPS results indicate that our fabricated compound is ...