Craig Foster, Civil and Materials Engineering and Sandeep Jain and Dimitri Azar, Ophthalmology and Visual Science, Philip Iannoccone, Children’s Memorial Hospital Primary Grant Support: NIH, UIC
Problem Statement and Motivation • • • Collagen cross-linking stiffens corneas weakened by keratoconus
Finite element modeling can help optimize procedure
We are developing models of normal, keratoconic, and and collagen cross-link treated corneas to determine quantities such as strain, stress, stiffness, and and shape under intraocular pressure. One major goal is to examine how the mechanical state of stress and strain influences patterns observed in cell formation and migration, including spiral formation in the epithelium. A second goal is to develop a model that can be used to predict the outcome of a specific treatment regimen of collagen cross-linking on a specific patient.
Cross-linking increases number of bonds between collagen fibers
Key Achievements and Future Goals
Technical Approach •
Multiscale models are developed using the stiffness curves of collagen fibrils oriented in different directions in the cornea (see below) and implemented in a finite element code.
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Once the traction-free geometry is determined, the intraocular pressure is added, and displace, strain, stress and other quantities of interest are determined.
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Development of anisotropic models based fibril orientation completed Parameter fitting and experimental validation under way Future work includes extending models to keratoconicc corneas and determining effect on cell pattern formation
Shear stress in a preliminary cornea model
Approximate orientations of collagen in the cornea
Raja Kaliappan1, Rachael Jones2, Karl J Rockne1 1Civil and Materials Engineering and 2Environmental and Occupational Health Sciences Funding from the Centers for Disease Control (CDC)
Problem Statement and Motivation •
This study attempts to link adverse pregnancy outcomes, birth defects and childhood leukemia to pre/postnatal exposure to atrazine and nitrate through drinking water
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Atrazine is a widely applied herbicide in the cultivation of corn, sorghum and sugarcane
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Atrazine is transported by surface runoff and infiltration leading to surface water and ground water contamination and subsequent human exposure through drinking water
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Atrazine is a known endocrine disruptor. Several studies show limited evidence of atrazine exposure to adverse reproductive/birth outcomes and childhood leukemia
Key Achievements and Future Goals
Technical Approach •
Collection of county level agrochemical data in drinking water from SIDWIS and adverse reproductive/birth outcomes from birth certificates from eight Midwestern states: Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio and Wisconsin
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Annual and monthly atrazine and nitrate exposure estimates
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Identification of potential confounders, correlation and multivariable regression (health-linkage) analysis of county level data
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Cluster detection, mixed effects model and geographically weighted regression using spatial statistical methods
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Drinking water data analysis shows that peak atrazine concentrations occur in the months of April to August, consistent with known application patterns
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County level annual and monthly average atrazine/nitrate exposures have been quantified for inclusion in a GIS database for spatial mapping
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These data will be linked with adverse pregnancy outcomes from public health data (birth records, birth defects, and cancer registries) for an environmental epidemiological study
Asha Rani, Azivy Aziz, Karl J. Rockne Department of Civil & Materials Engineering, University of Illinois at Chicago
Problem Statement and Motivation Sources of mercury to wastewater treatment systems are primarily from industrial sources and dental operations. Studies conducted by the University of Illinois at Chicago (UIC) revealed that a typical dental clinic can generate up to 4.5 g aqueous Hg waste/day. Our previous research demonstrated that elemental Hg from removed dental amalgam fillings is transformed to the highly toxic methyl Hg (MeHg) by sulfate-reducing bacteria (SRB).
Dental trap FLX amplicon pyrosequencing
Sequence analysis
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Key Achievements and Future Goals
Technical Approach • • • • • • • •
Dental wastewater (DWW) collection from dental traps Determination of total Hg and MeHg levels using mercury analyzer Metagenomic DNA isolation from samples Identification of novel bacteria by 16S rRNA gene sequencing Automated ribosomal intergenic spacer analysis (ARISA) on metagenomic DNA Quantitative-PCR for estimation of total eubacteria versus SRB High-throughput FLX amplicon pyrosequencing of all the samples to characterize total microbial communities Phylogentic analysis and identification of novel lineages
Key questions will be answered by this research: Where is Hg methylated? In the mouth or in the DWW system? How many and which Hg methylating bacterial species exist? What microbial communities can exist in the highly toxic DWW?
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Metagenomic DNA isolated from Hg contaminated DWW 16S rRNA gene has been amplified for pyrosequencing Q-PCR optimized for total eubacteria and SRB ARISA and pyrosequencing analysis in progress Phylogenetic analysis for identification and characterization of microbial community composition in progress
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Future goal to employ these techniques to understand microbial community structures in other high Hg environments worldwide • Minamata Bay, Japan: Estuarine • Soda lakes in Western USA: (pH 13) • Solar saltern in Spain: (>35% salt) • Hg mines, SW Alaska: Freshwater, cold
Sheng-Wei Chi, Department of Civil and Materials Engineering, UIC Primary Grant Support: UIC
Problem Statement and Motivation
Initial trial
Construction of muscle model from a stack of images
Characterization of material properties of tendon from in vivo MRI
Isometric study on the mechanics of passive materials in muscle
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The patient-specific computational modeling requires tremendous efforts to convert medical images to a 3D geometric representation and to a finite element mesh.
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The study aims to develop an image-based computational framework for modeling biological systems, such as, the musculoskeletal system.
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Seamlessly integrate CAD geometric representation with numerical simulation.
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Develop effective and accurate computational methods for modeling problems that exhibit fundamental difficulties, such as, incompressible, contact, and extremely large deformation problem.
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Understand better how muscles function and predict muscle force output.
Key Achievements and Future Goals
Technical Approach • • • •
Finite element analysis with mixed formulation Levelset based autonomous image segmentation 3D muscle morphology using levelset methods Anisotropic hyperelastic model for muscle 2
“3D Modeling of Complex Muscle Architecture and Geometry”, Dissertation, S.S.Blemker
W I1 , I 2 , I 4 , I 5 W I 3
total fiber
I1 I1 I 31/ 3 ,
I 2 I 2 I 32 / 3 ,
I 4 I 4 I 31/ 3 ,
I 5 I 5 I 32 / 3
3
act pass iso t f fiber * f fiber *
Anisotropic hyperelastic constitutive model for muscle
a0
1
Levelset based image segmentation
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Develop an image-based computational framework.
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Develop a levelset based method to autonomously construct the 3D geometry of muscle from images.
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Reveal and explain complex strain mechanics in the aponeuroses of contracting skeletal muscle.
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Study the passive material influence on the deformation and force output of skeletal muscle.
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The future work is to develop a multiscale constitutive model for muscle active contraction.
Karl J. Rockne, Department of Civil and Material Engineering An Li, Environmental and Occupational Health Sciences Neil C. Sturchio, Earth and Environmental Sciences Primary Grant Support : US. Environmental Protection Agency – Great Lakes National Program Office
Problem Statement and Motivation •
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Key Achievements and Future Goals
Technical Approach •
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Sediment samples collected through surface Ponar grabs, along with 25cm deep sediment cores retrieved at selected sites using an Ocean Instruments MC-400 “Spyder” Multi Corer. Physical/chemical characterization of sediment including elemental analysis of sediment organic matter, and pore-water ion composition.
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Age dating of sediments through radionuclide analysis and Gamma emission spectrometry.
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Chemical analysis for PBTs including polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), pesticides, and polybrominated diphenyl ethers (PDBE).
The mission of GLSSP is to investigate the presence of persistent, bioaccumulative, and toxic (PBT) chemicals, and reveal the spatial distribution and temporal trend of PBT pollution in the Great Lakes sedimentary record. Sediment is one of the largest depository matrices of pollutants in aquatic systems, and often acts as a secondary source even long after discharge ceases. Properly retrieved and preserved sediment samples can provide information valuable to the effective management and remediation of the contaminated water bodies. Although the Great Lakes have been one of the most investigated large freshwater systems, the number of region-wide studies on both legacy and emerging chemical pollutants in the sediment is still limited. A better understanding of the transport and transformation of PBT chemicals deposited in the sediments demands detailed characterization of the sediments and the over laying water column.
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Successful sediment sampling of deepest point in Lake Superior (385m depth) achieved, May 2011 Genetic assay of water column microbial genomes through pyrosequencing Investigation of in-situ dehalogenation of PBTs in sediment. Analysis of sediment mercury (Hg) and potential Hg-methylation.
Sampling Year Summer, 2010 Summer, 2011 Summer, 2012 Summer, 2013 Summer, 2014
Targeted Great Lakes, Bays and Rivers Lake Michigan, Green Bay Lake Superior Lake Huron, Lake St. Clair, Detroit River Lake Ontario, St. Lawrence River Lake Erie including Niagara River
# of Cores 11 11 10 8 7
# of Grabs 26 28 40 40 30
Eduard Karpov, CME Primary Grant Support: National Science Foundation
Problem Statement and Motivation •
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• • Typical deterministic multiscale modeling approach; Broughton, PRB 60(4)
Creep cavity in 304 austenitic steel, and its self-healing mechanism by BN surface precipitation; Shinya, IJMSS 17
Key Achievements and Future Goals
Technical Approach •
Continuum scale finite element model reflects the concurrent atomistic configuration via frequently updated material properties, while the kinetic Monte-Carlo model utilizes deformation parameters for an update of interatomic geometry and microscopic diffusion rates
Modern functional materials for engineering and medical applications are designed to perform a self-controlled smart action, similar to a living creature able to sense and process the environment and take necessary actions Self-healing materials is one important class of evolutionary smart materials The smart action is related to a progressive change of constitutive material properties at a macroscopic interval of time, governed by atomic scale processes Interplay between the mechanical performance and the internal structure dynamics can be two-way Deterministic multiscale modeling approaches with an atomistic resolution based on molecular dynamics are inadequate in application to the evolutionary materials, due to physical time limitations
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An efficient mechanokinetic coupling methodology has been developed and applied to the to biomimetic crack self-healing by surface precipitation under external mechanical loading Physical time is derived statistically from temporal characteristics of small scale processes to enable modeling over macroscopic intervals of physical time with an atomistic resolution Qualitative trends of the self-healing problem are compliant with experimental observations, while the modeling takes the analysis far beyond available empirical data and current experimental capabilities The proposed methodology is applicable to a wide class of evolutionary processes including strain dependant diffusion, nanostructure synthesis, material chemical transformations, surface chemical waves and adsorbate dynamics