Patient-Specific Bone Implants Using Subtractive Rapid Prototyping, 2017 Iowa State University
Patient-Specific Bone Implants Using Subtractive Rapid Prototyping, Matthew C. Frank, Ashish Mukund Joshi, Donald D. Anderson, Thaddeus P. Thomas, M. James Rudert, Yuki Tochigi, J. Lawrence Marsh, Thomas D. Brown
Matthew C. Frank
This research involves the development of rapid manufacturing for patient-specific bone implants using a Subtractive Rapid Prototyping process. The geometry of segmental defects in bone, resulting from traumatic injury or cancerous tumor resection, can be reverse-engineered from medical images (such as CT scans), and then accurate defect fillers can be automatically generated in advanced synthetic or otherwise bioactive/biocompatible materials. This paper presents a general process planning methodology that begins with CT imaging and results in the automatic generation of process plans for a subtractive RP system. This work uniquely enables the rapid manufacturing of implant fillers with several key ...
Creating Implants From Allograft Bone Using Subtractive Rapid Prototyping, 2017 Iowa State University
Creating Implants From Allograft Bone Using Subtractive Rapid Prototyping, Matthew C. Frank, Ashish Mukund Joshi, Shuangyan Lei, Donald D. Anderson, Yuki Tochigi, Thomas D. Brown
Matthew C. Frank
This research involves the development of rapid manufacturing for bone implants using human allograft bone in a Subtractive Rapid Prototyping process. Using CT-derived CAD models of missing bone due to high energy trauma or tumor resection, surgical reconstruction could be improved with custom rapid implants made from natural bone. The bone “stock” material is of arbitrary shape and material distribution in the form of frozen donated cadaveric bones. Each is unique in shape and has highly anisotropic material properties; likewise for each final bone implant geometry and its material distribution. This work utilizes a PLY input file, instead of the ...
Additive/Subtractive Rapid Pattern Manufacturing For Casting Patterns And Injection Mold Tooling, 2017 Iowa State University
Additive/Subtractive Rapid Pattern Manufacturing For Casting Patterns And Injection Mold Tooling, Matthew C. Frank, Frank Peters, Rajesh Kumar Karthikeyan
Matthew C. Frank
This paper presents a Rapid Pattern Manufacturing system that involves both additive and subtractive techniques whereby slabs are sequentially bonded and milled using layered toolpaths. Patterns are grown in a bottom-up fashion, both eliminating the need for multi-axis operations and allowing small features in deep cavities. Similar approaches exist in the literature; however, this system is able to provide a larger range of both materials and sizes, from smaller conventional injection mold tooling to very large wood or urethane sand casting patterns. This method introduces a novel sacrificial support structure approach by integrating a flask into the pattern build process ...
Evaluation Of The Display Of Cognitive State Feedback To Drive Adaptive Task Sharing, 2017 Iowa State University
Evaluation Of The Display Of Cognitive State Feedback To Drive Adaptive Task Sharing, Michael C. Dorneich, Břetislav Passinger, Christopher Hamblin, Claudia Keinrath, Jiři Vašek, Stephen D. Whitlow, Martijn Beekhuyzen
Industrial and Manufacturing Systems Engineering Publications
This paper presents an adaptive system intended to address workload imbalances between pilots in future flight decks. Team performance can be maximized when task demands are balanced within crew capabilities and resources. Good communication skills enable teams to adapt to changes in workload, and include the balancing of workload between team members This work addresses human factors priorities in the aviation domain with the goal to develop concepts that balance operator workload, support future operator roles and responsibilities, and support new task requirements, while allowing operators to focus on the most safety critical tasks. A traditional closed-loop adaptive system includes ...
Shift-Symmetric Configurations In Two-Dimensional Cellular Automata: Irreversibility, Insolvability, And Enumeration, 2017 University of Luxembourg
Shift-Symmetric Configurations In Two-Dimensional Cellular Automata: Irreversibility, Insolvability, And Enumeration, Peter Banda, John S. Caughman Iv, Martin Cenek, Christof Teuscher
Mathematics and Statistics Faculty Publications and Presentations
The search for symmetry as an unusual yet profoundly appealing phenomenon, and the origin of regular, repeating configuration patterns have been for a long time a central focus of complexity science, and physics.
Here, we introduce group-theoretic concepts to identify and enumerate the symmetric inputs, which result in irreversible system behaviors with undesired effects on many computational tasks. The concept of so-called configuration shift-symmetry is applied on two-dimensional cellular automata as an ideal model of computation. The results show the universal insolvability of “non-symmetric” tasks regardless of the transition function. By using a compact enumeration formula and bounding the number ...
Rapid Manufacturing In Biomedical Materials: Using Subtractive Rapid Prototyping For Bone Replacement, 2017 Iowa State University
Rapid Manufacturing In Biomedical Materials: Using Subtractive Rapid Prototyping For Bone Replacement, Matthew C. Frank, Christopher V. Hunt, Donald D. Anderson, Todd O. Mckinley, Thomas D. Brown
Matthew C. Frank
This paper presents methods for the rapid manufacturing of replacement bone fragments using a Subtractive Rapid Prototyping process called CNC-RP. The geometry of segmental defects in bone, resulting from traumatic injury or cancerous tumor resection, can be reverse-engineered working from medical images (such as CT scans), and then accurate defect fillers can be automatically generated in advanced synthetic biomaterials and other bioactive/biocompatible materials. The research provides evidence that suitable bone geometries can be created using subtractive RP from a variety of materials including Trabecular Metal® (porous tantalum), polymers, ceramics, and actual bone allografts. The research has implications in the ...
Advanced Process Planning For Subtractive Rapid Prototyping, 2017 Iowa State University
Advanced Process Planning For Subtractive Rapid Prototyping, Joseph Edward Petrzelka, Matthew C. Frank
Matthew C. Frank
This paper presents process planning methods for Subtractive Rapid Prototyping, which deals with multiple setup operations and the related issues of stock material management. Subtractive Rapid Prototyping (SRP) borrows from additive rapid prototyping technologies by using 2½D layer based toolpath processing; however, it is limited by tool accessibility. To counter the accessibility problem, SRP systems (such as desktop milling machines) employ a rotary fourth axis to provide more complete surface coverage. However, layer-based removal processing from different rotary positions can be inefficient due to double-coverage of certain volumes. This paper presents a method that employs STL models of the in-process ...
Economics Of Sacrificial Fixturing For Cnc Machining And Rapid Manufacturing, 2017 The Pennsylvania State University
Economics Of Sacrificial Fixturing For Cnc Machining And Rapid Manufacturing, Kevin Mcbrearty, Richard A. Wysk, Matthew C. Frank
Matthew C. Frank
This paper presents a fixturing method for sacrificial fixturing machining using CNC equipment. The focus of the paper is not on the method itself, but on the economics of sacrificial fixturing CNC machining, which defines the domain of use for the results described in the paper. The paper presents an economic model of machining, and then analyzes the use of the method as a function of: the number of parts to be produced, the ratio of material removed to final part volume, the number of features on the part, and the basic part geometry. We conclude that sacrificial fixturing is ...
Implementing Rapid Prototyping Using Cnc Machining (Cnc-Rp) Through A Cad/Cam Interface, 2017 Iowa State University
Implementing Rapid Prototyping Using Cnc Machining (Cnc-Rp) Through A Cad/Cam Interface, Matthew C. Frank
Matthew C. Frank
This paper presents the methodology and implementation of a rapid machining system using a CAD/CAM interface. Rapid Prototyping using CNC Machining (CNC-RP) is a method that has been developed which enables automatic generation of process plans for a machined component. The challenge with CNC-RP is not the technical problems of material removal, but with all of the required setup, fixture and toolpath planning, which has previously required a skilled machinist. Through the use of advanced geometric algorithms, we have implemented an interface with a CAD/CAM system that allows true automatic NC code generation directly from a CAD model ...
Automated Fixture Design For A Rapid Machining Process, 2017 Iowa State University
Automated Fixture Design For A Rapid Machining Process, Wutthigrai Boonsuk, Matthew C. Frank
Matthew C. Frank
Rapid prototyping techniques for CNC machining have been developed in an effort to produce functional prototypes in appropriate materials. One of the major challenges for rapid machining is to develop an automatic fixturing system for securing the part during the machining process. The method proposed in this paper is the use of sacrificial fixturing, similar to the support structures in existing rapid processes like Stereolithography. During the machining process, sacrificial supports emerge incrementally and, at the end of the process, are the only entities connecting the part to the stock material. This paper presents methodologies for the design of sacrificial ...
A Computational/Experimental Platform For Investigating Three- Dimensional Puzzle Solving Of Comminuted Articular Fractures, Thaddeus P. Thomas, Donald D. Anderson, Andrew Willis, Pengcheng Liu, Matthew C. Frank, J. Lawrence Marsh, Thomas D. Brown
Matthew C. Frank
Reconstructing highly comminuted articular fractures poses a difficult surgical challenge, akin to solving a complicated three-dimensional (3D) puzzle. Pre-operative planning using CT is critically important, given the desirability of less invasive surgical approaches. The goal of this work is to advance 3D puzzle solving methods toward use as a pre-operative tool for reconstructing these complex fractures. Methodology for generating typical fragmentation/dispersal patterns was developed. Five identical replicas of human distal tibia anatomy, were machined from blocks of high-density polyetherurethane foam (bone fragmentation surrogate), and were fractured using an instrumented drop tower. Pre- and post-fracture geometries were obtained using laser ...
A Method To Represent Heterogeneous Materials For Rapid Prototyping: The Matryoshka Approach, 2017 Iowa State University
A Method To Represent Heterogeneous Materials For Rapid Prototyping: The Matryoshka Approach, Shuangyan Lei, Matthew C. Frank, Donald D. Anderson, Thomas D. Brown
Matthew C. Frank
Purpose—The purpose of this paper is to present a new method for representing heterogeneous materials using nested STL shells, based, in particular, on the density distributions of human bones.
Design/methodology/approach—Nested STL shells, called Matryoshka models, are described, based on their namesake Russian nesting dolls. In this approach, polygonal models, such as STL shells, are “stacked” inside one another to represent different material regions. The Matryoshka model addresses the challenge of representing different densities and different types of bone when reverse engineering from medical images. The Matryoshka model is generated via an iterative process of thresholding the ...
Maximum Soil Organic Carbon Storage In Midwest U.S. Cropping Systems When Crops Are Optimally Nitrogen-Fertilized, Hanna J. Poffenbarger, Daniel W. Barker, Matthew J. Helmers, Fernando E. Miguez, Daniel C. Olk, John E. Sawyer, Johan Six, Michael J. Castellano
John E. Sawyer
Nitrogen fertilization is critical to optimize short-term crop yield, but its long-term effect on soil organic C (SOC) is uncertain. Here, we clarify the impact of N fertilization on SOC in typical maize-based (Zea mays L.) Midwest U.S. cropping systems by accounting for site-to-site variability in maize yield response to N fertilization. Within continuous maize and maize-soybean [Glycine max (L.) Merr.] systems at four Iowa locations, we evaluated changes in surface SOC over 14 to 16 years across a range of N fertilizer rates empirically determined to be insufficient, optimum, or excessive for maximum maize yield. Soil organic C ...
Effect Of Anthropometric Adjustments On Bmd And Bmc Z-Scores In A Population Of Prader-Willi Syndrome Pediatric Patients, 2017 Wright State University
Effect Of Anthropometric Adjustments On Bmd And Bmc Z-Scores In A Population Of Prader-Willi Syndrome Pediatric Patients, Amanda E. Marker, David F. Short, Talia Eldar-Geva, Harry J. Hirsch, Varda Gross-Tsur, Maayan Tiomkin, Ari Zimran, Thomas N. Hangartner
Thomas N. Hangartner
Two adjustment models were applied to a dataset of bone-mineral density (BMD) and bone-mineral content (BMC) from dual-energy x-ray absorptiometry (DXA) measurements of pediatric patients with Prader-Willi Syndrome (PWS). One model used weight, height and % body fat (WHF) in the calculation of Z-scores in addition to race, sex and age already included in the standard model. As percent body fat is not always available, a second model with only weight and height was also examined (WH).
Nanomaterials Synthesis, Applications, And Toxicity 2012, 2017 Wright State University - Main Campus
Nanomaterials Synthesis, Applications, And Toxicity 2012, Mallikarjuna Nadagouda, Dionysios Demetriou Dionysiou, Darren A. Lytle, Thomas F. Speth, Sharmila M. Mukhopadhyay
Sharmila M. Mukhopadhyay
Nanotechnology presents new opportunities to create better materials and products. Nanomaterials find wide applications in catalysis, energy production, medicine, environmental remediation, automotive industry, and other sectors of our society. Nanomaterial-containing products are already available globally and include automotive parts, defense application, drug delivery devices, coatings, computers, clothing, cosmetics, sports equipment, and medical devices. This special issue includes emerging advances in the field, with a special emphasis given to nanomaterial synthesis and applications.
Reasoning Strategies In The Context Of Engineering Design With Everyday Materials, 2017 Northwestern University
Reasoning Strategies In The Context Of Engineering Design With Everyday Materials, Marcelo Worsley, Paulo Blikstein
Journal of Pre-College Engineering Education Research (J-PEER)
‘‘Making’’ represents an increasingly popular label for describing a form of engineering design. While making is growing in popularity, there are still open questions about the strategies that students are using in these activities. Assessing and improving learning in making/ engineering design contexts require that we have a better understanding of where students’ ideas are coming from and a better way to characterize student progress in open-ended learning environments. In this article, we use a qualitative analysis of students’ responses (N = 13) in order to identify the origins of their ideas. Four strategies emerged from this analysis: unexplained reasoning; materials-based ...
Half-Metallic Co-Based Quaternary Heusler Alloys For Spintronics: Defect- And Pressure-Induced Transitions And Properties, 2017 Indian Institute of Technology Bombay
Half-Metallic Co-Based Quaternary Heusler Alloys For Spintronics: Defect- And Pressure-Induced Transitions And Properties, Enamullah, D. D. Johnson, K. G. Suresh, Aftab Alam
Duane D. Johnson
Heusler compounds offer potential as spintronic devices due to their spin polarization and half-metallicity properties, where electron spin-majority (minority) manifold exhibits states (band gap) at the electronic chemical potential, yielding full spin polarization in a single manifold. Yet, Heuslers often exhibit intrinsic disorder that degrades its half-metallicity and spin polarization. Using density-functional theory, we analyze the electronic and magnetic properties of equiatomic Heusler (L21) CoMnCrAl and CoFeCrGe alloys for effects of hydrostatic pressure and intrinsic disorder (thermal antisites, binary swaps, and vacancies). Under pressure, CoMnCrAl undergoes a metallic transition, while half-metallicity in CoFeCrGe is retained for a limited range. Antisite ...
Origin Of Magnetic Anisotropy In Doped Ce2co17 Alloys, 2017 Ames Laboratory
Origin Of Magnetic Anisotropy In Doped Ce2co17 Alloys, Liqin Ke, D. A. Kukusta, Duane D. Johnson
Duane D. Johnson
Magnetocrystalline anisotropy (MCA) in doped Ce2Co17 and other competing structures was investigated using density functional theory. We confirmed that the MCA contribution from dumbbell Co sites is very negative. Replacing Co dumbbell atoms with a pair of Fe or Mn atoms greatly enhance the uniaxial anisotropy, which agrees quantitatively with experiment, and this enhancement arises from electronic-structure features near the Fermi level, mostly associated with dumbbell sites. With Co dumbbell atoms replaced by other elements, the variation of anisotropy is generally a collective effect and contributions from other sublattices may change significantly. Moreover, we found that Zr doping promotes the ...
Large Energy Product Enhancement In Perpendicularly Coupled Mnbi/Cofe Magnetic Bilayers, 2017 University of Maryland at College Park
Large Energy Product Enhancement In Perpendicularly Coupled Mnbi/Cofe Magnetic Bilayers, T. R. Gao, L. Fang, S. Fackler, S. Maruyama, X. H. Zhang, L. L. Wang, T. Rana, P. Manchanda, A. Kashyap, K. Janicka, A. L. Wysocki, A. T. N'Diaye, E. Arenholz, J. A. Borchers, B. J. Kirby, B. B. Maranville, K. W. Sun, M. J. Kramer, V. P. Antropov, D. D. Johnson, R. Skomski, J. Cui, I. Takeuchi
Duane D. Johnson
We demonstrate substantial enhancement in the energy product of MnBi-based magnets by forming robust ferromagnetic exchange coupling between a MnBi layer and a thin CoFe layer in a unique perpendicular coupling configuration, which provides increased resistance to magnetization reversal. The measured nominal energy product of 172kJ/m3 at room temperature is the largest value experimentally attained for permanent magnets free of expensive raw materials. Our finding shows that exchange-coupled MnBi/CoFe magnets are a viable option for pursuing rare-earth-free magnets with energy products approaching those containing rare-earth elements.
Impact Of 4r Management On Crop Production And Nitrate-Nitrogen Loss In Tile Drainage, 2017 Iowa State University
Impact Of 4r Management On Crop Production And Nitrate-Nitrogen Loss In Tile Drainage, Matthew Helmers, John Sawyer, Carl Pederson
John E. Sawyer
Corn Belt corn and soybean producers are increasingly challenged to maximize crop production while addressing the contributions farm practices make to Gulf hypoxia. Based on the need for nitrate-N reductions in surface water systems to meet water quality goals, new management practices are needed to reduce nitrate-N losses at minimal cost and maximum economic benefits. This three-year field research and demonstration project is evaluating various promising N management methods and technologies by documenting the nitrate-N export and crop yield from various systems.