Engineering Commons^™

Hyperelastic Modeling Of Wide-Base Tire And Prediction Of Its Contact Stresses, Jaime Hernandez, Imad L. Al-Qadi

Civil and Environmental Engineering Faculty Research and Publications

Description of tire model development using the finite element (FE) method is presented. Three-dimensional tire-pavement contact stresses were predicted for braking, traction, and free rolling using the FE method. Measured load-deflection curves, contact area, and contact stresses were used for model outcome validation. Slide-velocity-dependent friction and accurate input regarding geometry and material properties were considered. The developed tire model, which helped in studying contact stresses variation in each direction, was used to explain the various phenomena taking place at the tire-pavement interface during straight-line rolling. The analysis matrix includes nine rolling conditions and various loads, tire inflation pressures, and speeds. …

Online Chemical Sensor Signal Processing Using Estimation Theory: Quantification Of Binary Mixtures Of Organic Compounds In The Presence Of Linear Baseline Drift And Outliers, Karthick Sothivelr, Florian Bender, Fabien Josse, Edwin E. Yaz, Antonio J. Ricco, Mary E. Mohler

Electrical and Computer Engineering Faculty Research and Publications

Compact sensor systems for on-site monitoring of groundwater for trace organic compounds in the liquid phase are currently under development in our laboratories. Potential challenges include sensor baseline drift and the presence of outliers in the data, along with difficulties extracting the contribution of individual BTEX compound (benzene, toluene, ethylbenzene, and xylenes) from the sensor response to mixtures containing multiple chemically similar compounds. As a first step, the approach presented here permits online estimation of analyte concentrations in binary mixtures of BTEX compounds in the presence of linear baseline drift and outliers. This paper investigates a sensor signal-processing approach based …

Robust Non-Permanent Magnet Motors For Vehicle Propulsion, Tsarajidy Raminosoa, David A. Torrey, Ayman M. El-Refaie, Di Pan, Stefan Grubic, Kevin Grace

Electrical and Computer Engineering Faculty Research and Publications

There has been growing interest in electrical machines that reduce or eliminate rare-earth material content. Traction applications are among the key applications where reducing cost and hence reduction or elimination of rare-earth materials is a key requirement. This paper will assess the potential of three non-permanent magnet options in the context of vehicle propulsion applications: 1) a conventional Switched Reluctance Machine (SRM), 2) a DC-biased Reluctance Machine (DCRM) and, 3) a Wound Field Flux Switching Machine (WFFSM). The three machines were designed to achieve the hybrid vehicle traction requirements of 55kW peak and 30kW continuous over a speed range going …

Effects Of Intraframe Distortion On Measures Of Cone Mosaic Geometry From Adaptive Optics Scanning Light Ophthalmoscopy, Robert F. Cooper, Yusufu N. Sulai, Adam M. Dubis, Toco Y.P. Chui, Richard B. Rosen, Michel Michaelides, Alfredo Dubra, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Purpose: To characterize the effects of intraframe distortion due to involuntary eye motion on measures of cone mosaic geometry derived from adaptive optics scanning light ophthalmoscope (AOSLO) images.

Methods: We acquired AOSLO image sequences from 20 subjects at 1.0, 2.0, and 5.08 temporal from fixation. An expert grader manually selected 10 minimally distorted reference frames from each 150-frame sequence for subsequent registration. Cone mosaic geometry was measured in all registered images (n ¼ 600) using multiple metrics, and the repeatability of these metrics was used to assess the impact of the distortions from each reference frame. In nine additional subjects, …

Acoustic Sequences In Non-Human Animals: A Tutorial Review And Prospectus, Arik Kershenbaum, Daniel T. Blumstein, Marie A. Roch, Çağlar Akçay, Gregory Backus, Mark A. Bee, Kirsten Bohn, Yan Cao, Gerald Carter, Cristiane Cäsar, Michael Coen, Stacy L. Deruiter, Laurance Doyle, Shimon Edelman, Ramon Ferreri Cancho, Todd M. Freeberg, Ellen C. Garland, Morgan Gustison, Heidi E. Harley, Chloé Huetz, Melissa Hughes, Julia Hyland Bruno, Amiyaal Ilany, Dezhe Z. Jin, Michael T. Johnson, Chenghui Ju, Jeremy Karnowski, Bernard Lohr, Marta B. Manser, Brenda Mccowan, Eduardo Mercado Iii, Peter M. Narins, Alex Piel, Megan Rice, Roberta Salmi, Kazutoshi Sasahara, Laela Sayigh, Yu Shiu, Charles Taylor, Edgar E. Vallejo, Sara Waller, Veronica Zamora Gutierrez

Electrical and Computer Engineering Faculty Research and Publications

Animal acoustic communication often takes the form of complex sequences, made up of multiple distinct acoustic units. Apart from the well-known example of birdsong, other animals such as insects, amphibians, and mammals (including bats, rodents, primates, and cetaceans) also generate complex acoustic sequences. Occasionally, such as with birdsong, the adaptive role of these sequences seems clear (e.g. mate attraction and territorial defence). More often however, researchers have only begun to characterise – let alone understand – the significance and meaning of acoustic sequences. Hypotheses abound, but there is little agreement as to how sequences should be defined and analysed. Our …

On The Role Of Adsorbate Position, Geometry, And Binding Characteristics On The Multi-Modal Response Of Cantilever-Based Resonators For Higher-Order Discrete-Mass Detection, Stephen M. Heinrich, Pierre-Henri Ducrot, C. Ayela, Hongjian Zhang, Isabelle Dufour

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.

Assessing Postural Stability Via The Correlation Patterns Of Vertical Ground Reaction Force Components, Chih-Yuan Hong, Lan-Yuen Guo, Rong Song, Mark L. Nagurka, Jia-Li Sung, Chen-Wen Yen

Mechanical Engineering Faculty Research and Publications

Background

Many methods have been proposed to assess the stability of human postural balance by using a force plate. While most of these approaches characterize postural stability by extracting features from the trajectory of the center of pressure (COP), this work develops stability measures derived from components of the ground reaction force (GRF).

Methods

In comparison with previous GRF-based approaches that extract stability features from the GRF resultant force, this study proposes three feature sets derived from the correlation patterns among the vertical GRF (VGRF) components. The first and second feature sets quantitatively assess the strength and changing speed of …

A Simple Kinetic Analysis Of Syngas During Steam Hydrogasification Of Biomass Using A Novel Inverted Batch Reactor With Instant High Pressure Feeding, Xin Fan, Zhongzhe Liu, Joseph M. Norbeck, Chan S. Park

Civil and Environmental Engineering Faculty Research and Publications

A newly designed inverted batch reactor equipped with a pressure-driven feeding system was built for investigating the kinetics of syngas during the steam hydrogasification (SHR) of biomass. The system could instantly load the feedstock into the reactor at high temperature and pressure, which simulated the way to transport the feedstock into a hot and pressurized gasifier. Experiments were conducted from 600 °C to 700 °C. The inverted reactor showed very high heating rate by enhancing the carbon conversion and syngas production. The kinetic study showed that the rates of CH₄, CO and CO₂ formation during SHR were …

Chronic Exposure To Triclosan Sustains Microbial Community Shifts And Alters Antibiotic Resistance Gene Levels In Anaerobic Digesters, Daniel Elliott Carey, Daniel Zitomer, Anthony D. Kappell, Melinda J. Choi, Krassimira R. Hristova, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Triclosan, an antimicrobial chemical found in consumer personal care products, has been shown to stimulate antibiotic resistance in pathogenic bacteria. Although many studies focus on antibiotic resistance pertinent to medical scenarios, resistance developed in natural and engineered environments is less studied and has become an emerging concern for human health. In this study, the impacts of chronic triclosan (TCS) exposure on antibiotic resistance genes (ARGs) and microbial community structure were assessed in lab-scale anaerobic digesters. TCS concentrations from below detection to 2500 mg kg⁻¹ dry solids were amended into anaerobic digesters over 110 days and acclimated for >3 solid …

Emerging Investigators Series: Pyrolysis Removes Common Microconstituents Triclocarban, Triclosan, And Nonylphenol From Biosolids, J. J. Ross, Daniel Zitomer, T. R. Miller, C. A. Weirich, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Reusing biosolids is vital for the sustainability of wastewater management. Pyrolysis is an anoxic thermal degradation process that can be used to convert biosolids into energy rich py-gas and py-oil, and a beneficial soil amendment, biochar. Batch biosolids pyrolysis (60 minutes) revealed that triclocarban and triclosan were removed (to below quantification limit) at 200 °C and 300 °C, respectively. Substantial removal (>90%) of nonylphenol was achieved at 300 °C as well, but 600 °C was required to remove nonylphenol to below the quantification limit. At 500 °C, the pyrolysis reaction time to remove >90% of microconstituents was less than …

Transient Analysis Of Analyte Desorption Due To Thermal Cycling With Varying Pulse Duration, Patrick Getz, Christopher Carron, Stephen M. Heinrich, Fabien Josse, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

This paper introduces heating pulse duration modulation on a chemically sensitive, polymer-coated resonant cantilever platform for analyte discrimination during the desorption phase. As in our previous work, the embedded heaters enable real-time measurements of analyte sorption into the polymer film, without the need for traditional valve systems and reference gases [1-2]. This work particularly looks at the effects of varying pulse lengths on the sensor responses, while holding the heating power constant. A model differential equation is developed for the sensor response based on both the device sensitivity and transient response. This model can then be used together with estimation …

Total Value Of Phosphorus Recovery, Brooke K. Mayer, Lawrence A. Baker, Treavor H. Boyer, Pay Drechsel, Mac Gifford, Munir A. Hanjra, Prathap Parameswaran, Jared Stoltzfus, Paul Westerhoff, Bruce E. Rittmann

Civil and Environmental Engineering Faculty Research and Publications

Phosphorus (P) is a critical, geographically concentrated, nonrenewable resource necessary to support global food production. In excess (e.g., due to runoff or wastewater discharges), P is also a primary cause of eutrophication. To reconcile the simultaneous shortage and overabundance of P, lost P flows must be recovered and reused, alongside improvements in P-use efficiency. While this motivation is increasingly being recognized, little P recovery is practiced today, as recovered P generally cannot compete with the relatively low cost of mined P. Therefore, P is often captured to prevent its release into the environment without beneficial recovery and reuse. However, additional …

Triclocarban Influences Antibiotic Resistance And Alters Anaerobic Digester Microbial Community Structure, Daniel Elliott Carey, Daniel Zitomer, Krassimira R. Hristova, Anthony D. Kappell, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Triclocarban (TCC) is one of the most abundant organic micropollutants detected in biosolids. Lab-scale anaerobic digesters were amended with TCC at concentrations ranging from the background concentration of seed biosolids (30 mg/kg) to toxic concentrations of 850 mg/kg to determine the effect on methane production, relative abundance of antibiotic resistance genes, and microbial community structure. Additionally, the TCC addition rate was varied to determine the impacts of acclimation time. At environmentally relevant TCC concentrations (max detect = 440 mg/kg), digesters maintained function. Digesters receiving 450 mg/kg of TCC maintained function under gradual TCC addition, but volatile fatty acid concentrations increased, …

Triclosan Adsorption Using Wastewater Biosolids-Derived Biochar, Yiran Tong, Brooke K. Mayer, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Organic micropollutants are ubiquitous in the environment and stem from municipal wastewater treatment plant discharges. Adsorption can be used as a tertiary treatment to complement the conventional activated sludge process to remove micropollutants prior to discharge. This research evaluated the performance of wastewater biosolids-derived biochar as an adsorbent to remove triclosan from water. Pre-conditioning of the biochar using hydrochloric acid (HCl) was an essential step for triclosan adsorption. Using acid-conditioned biochar, maximum adsorption of 872 μg triclosan per g biochar was achieved with biochar produced at 800 °C. Biochar produced at higher pyrolysis temperatures tended to have higher triclosan sorption …

Fluoroscopic System For Assessment Of In Vivo Hindfoot Kinematics During Gait: Control Data And Applications In Osteogenesis Imperfecta, Ben Mchenry, Jason Long, Peter Smith, Haluk Altiok, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Nih Visible Human Project Humerus Numerical And Physical Models: Characterization For Osteogenesis Imperfecta Fracture Study, Prateek Grover, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Quantitative Assessment Of Children With Osteogenesis Imperfecta, Adam Graf, Joseph Krzak, Angela Caudill, Ann Flanagan, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Assessments of children with Osteogenesis Imperfecta (OI) are typically limited to a physical exam and observations from a clinician during a hospital visit. Often quantitative information such as bone mineral density and outcome questionnaires is obtained, but with the increasing prevalence of motion analysis and other performance type laboratories, there are many other tools available, which could be beneficial to this patient population. These laboratories can provide date supplementary to morphologic and radiographic data that is helpful in tracking changes in the patient’s functional abilities, recover from fracture, and treatment outcomes. This chapter will cover some useful evaluation methods for …

Walker Design For Kinetic Assessment Of Upper Extremity Joint Demands In Children With Osteogenesis Imperfecta, Katherine A. Konop, Kelly M.B. Strifling, Mei Wang, Jeffrey P. Schwab, Jeffrey D. Ackman, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Motor Output Variability Impairs Driving Ability In Older Adults, Neha Lodha, Hwasil Moon, Changki Kim, Tanya Onushko, Evangelos A. Christou

Biomedical Engineering Faculty Research and Publications

Background: The functional declines with aging relate to deficits in motor control and strength. In this study, we determine whether older adults exhibit impaired driving as a consequence of declines in motor control or strength.

Methods: Young and older adults performed the following tasks: (i) maximum voluntary contractions of ankle dorsiflexion and plantarflexion; (ii) sinusoidal tracking with isolated ankle dorsiflexion; and (iii) a reactive driving task that required responding to unexpected brake lights of the car ahead. We quantified motor control with ankle force variability, gas position variability, and brake force variability. We quantified reactive driving performance with a combination …

Comparing Offline Decoding Performance In Physiologically Defined Neuronal Classes, Matthew D. Best, Kazutaka Takahashi, Aaron J. Suminski, Christian Ethier, Lee E. Miller, Nicholas G. Hatsopoulos

Biomedical Engineering Faculty Research and Publications

Objective: Recently, several studies have documented the presence of a bimodal distribution of spike waveform widths in primary motor cortex. Although narrow and wide spiking neurons, corresponding to the two modes of the distribution, exhibit different response properties, it remains unknown if these differences give rise to differential decoding performance between these two classes of cells. Approach: We used a Gaussian mixture model to classify neurons into narrow and wide physiological classes. Using similar-size, random samples of neurons from these two physiological classes, we trained offline decoding models to predict a variety of movement features. We compared offline …

Finite Element Modeling And Analysis Applications In Osteogenesis Imperfecta, Jessica M. Fritz, Nicole M. Grosland, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Understanding the biomechanics of bones in persons with osteogenesis imperfecta (OI) is a key component to further understanding the disease, optimizing treatment and quality of life, as well as injury prevention. However, it is not feasible to study bone biomechanics in vivo. Thus, modeling may play a key role in understanding how OI bones respond to the loading experienced during various activities, especially ambulation. Biomechanical modeling can provide insight into bone fracture risks, such as type and location, from single applied loads or repetitive loading. One method for obtaining this information is via a finite element analysis (FEA). FEA is …

Upper Extremity Inverse Dynamics Model For Loftstrand Crutch-Assisted Gait In Children With Osteogenesis Imperfecta, Brooke A. Slavens, Neha Bhagchandani, Mei Wang, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Role Of Micro-Ct In The Visualization, Measurement, And Quantification Of Bone Structure In Osteogenesis Imperfecta, Robert C. Molthen, John Jameson, Carolyne Albert, Peter Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

No abstract provided.

Assessing The Spatial Relationship Between Fixation And Foveal Specializations, Melissa A. Wilk, Adam M. Dubis, Robert F. Cooper, Phyllis Summerfelt, Alfredo Dubra, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Increased cone photoreceptor density, an avascular zone (FAZ), and the displacement of inner retinal neurons to form a pit are distinct features of the human fovea. As the fovea provides the majority of our vision, appreciating how these anatomical specializations are related is important for understanding foveal development, normal visual function, and retinal disease. Here we evaluated the relationship between these specializations and their location relative to the preferred retinal locus of fixation (PRL). We measured foveal pit volume, FAZ area, peak cone density, and location of the PRL in 22 subjects with normal vision using optical coherence tomography and …

Detection And Quantification Of Aromatic Hydrocarbon Compounds In Water Using Sh-Saw Sensors And Estimation-Theory-Based Signal Processing, Karthick Sothivelr, Florian Bender, Fabien Josse, Antonio J. Ricco, Edwin E. Yaz, Rachel E. Mohler, Ravi Kolhatkar

Electrical and Computer Engineering Faculty Research and Publications

This work investigates a sensor system for direct groundwater monitoring, capable of aqueous-phase measurement of aromatic hydrocarbons at low concentrations (about 100 parts per billion (ppb)). The system is designed to speciate and quantify benzene, toluene, and ethylbenzene/xylenes (BTEX) in the presence of potential interferents. The system makes use of polymer-coated shear-horizontal surface acoustic wave devices and a signal processing method based on estimation theory, specifically a bank of extended Kalman filters (EKFs). This approach permits estimation of BTEX concentrations even from noisy data, well before the sensor response reaches equilibrium. To utilize estimation theory, an analytical model for the …

Robust Multi-Criteria Optimal Fuzzy Control Of Continuous-Time Nonlinear Systems, Xin Wang, Edwin E. Yaz

Electrical and Computer Engineering Faculty Research and Publications

This paper presents a novel fuzzy control design of continuous-time nonlinear systems with multiple performance criteria. The purpose behind this work is to improve the traditional fuzzy controller performance to satisfy several performance criteria simultaneously to secure quadratic optimality with inherent stability property together with dissipativity type of disturbance reduction. The Takagi– Sugeno fuzzy model is used in our control system design. By solving the linear matrix inequality at each time step, the control solution can be found to satisfy the mixed performance criteria. The effectiveness of the proposed technique is demonstrated by simulation of the control of the inverted …

Severity Of Spinal Cord Injury Influences Diffusion Tensor Imaging Of The Brain, Michael B. Jirjis, Aditya Vedantam, Matthew D. Budde, Benjamin Kalinosky, Shekar N. Kurpad

Biomedical Engineering Faculty Research and Publications

Background: The purpose of this study was to determine whether DTI changes in the brain induced by a thoracic spinal cord injury are sensitive to varying severity of spinal contusion in rats.

Methods: A control, mild, moderate, or severe contusion injury was administered over the eighth thoracic vertebral level in 32 Sprague-Dawley rats. At 11 weeks postinjury, ex vivo DTI of the brain was performed on a 9.4T Bruker scanner using a pulsed gradient spin-echo sequence.

Results: Mean water diffusion in the internal capsule regions of the brain and pyramid locations of the brainstem were correlated with motor function (r …

Automated Selection Of The Optimal Cardiac Phase For Single-Beat Coronary Ct Angiography Reconstruction, Daniel Stassi, S. Dutta, H. Ma, A. Soderman, D. Pazzani, E. Gros, D. Okerlund, Taly Gilat-Schmidt

Biomedical Engineering Faculty Research and Publications

Purpose: Reconstructing a low-motion cardiac phase is expected to improve coronary artery visualization in coronary computed tomography angiography (CCTA) exams. This study developed an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. The algorithm uses prospectively gated, single-beat, multiphase data made possible by wide cone-beam imaging. The proposed algorithm differs from previous approaches because the optimal phase is identified based on vessel image quality (IQ) directly, compared to previous approaches that included motion estimation and interphase processing. Because there is no processing of interphase information, the algorithm can be applied to any sampling of image phases, …

Assessing Photoreceptor Structure Associated With Ellipsoid Zone Disruptions Visualized With Optical Coherence Tomography, Drew Scoles, John A. Flatter, Robert F. Cooper, Christopher S. Langlo, Scott Robison, Maureen Neitz, David V. Weinberg, Mark E. Pennesi, Dennis P. Han, Alfredo Dubra, Joseph Carroll

Biomedical Engineering Faculty Research and Publications

Purpose: To compare images of photoreceptor layer disruptions obtained with optical coherence tomography (OCT) and adaptive optics scanning light ophthalmoscopy (AOSLO) in a variety of pathologic states.

Methods: Five subjects with photoreceptor ellipsoid zone disruption as per OCT and clinical diagnoses of closed-globe blunt ocular trauma (n = 2), macular telangiectasia type 2 (n = 1), blue-cone monochromacy (n = 1), or cone-rod dystrophy (n = 1) were included. Images were acquired within and around photoreceptor lesions using spectral domain OCT, confocal AOSLO, and split-detector AOSLO.

Results: There were substantial differences in the extent and appearance of the photoreceptor mosaic …

Biomechanics Of Osteogenesis Imperfecta: Current Concepts And Emerging Horizons, Carolyne Albert, Jessica M. Fritz, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Osteogenesis inperfecta (OI) is associated with bone fragility. Long bone fractures are a common occurrence in individuals with OI. Although there have been significant advances in understanding the genetic defects associated with OI, the mechanisms behind bone fragility in this patient population are not yet well understood. This fragility is believed to stem in part from characteristic bone mass deficiencies. Research further suggests that the material properties of the bone are also compromised in individuals with this disorder. There is currently on quantitative method available to assess bone fracture risk in individuals with OI. This chapter examines several critical elements …