Civil and Environmental Engineering Commons^™

Lateral-Mode Vibration Of Microcantilever-Based Sensors In Viscous Fluids Using Timoshenko Beam Theory, Joshua Schultz

Dissertations (1934 -)

Dynamic-mode microcantilever-based devices are well suited to biological and chemical sensing applications. However, these applications often necessitate liquid-phase sensing, introducing significant fluid-induced dissipative forces and reducing device quality factors (Q). Recent experimental and analytical research has shown that higher in- fluidQis achieved by exciting microcantilevers in the lateral flexural mode. However, the experimental results show that, for microcantilevers having larger width-to-length (b/L) ratios, the behaviors predicted by current analytical models differ from measurements.

To more accurately model microcantilever resonant behavior in viscous fluids and to improve understanding of lateral-mode sensor performance, a new analytical model is developed, incorporating both viscous …

Preservation Of Methanogenic Cultures To Enhance Anaerobic Digestion, Ujwal H. Bhattad

Dissertations (1934 -)

The use of anaerobic biotechnology is increasing as a sustainable process to treat various organic wastes. Methanogens convert organic COD into CH4 and play the key role to drive thermodynamically unfavorable biochemical fermentation reactions and keep the digestion process steady and efficient. Progressive understanding of anaerobic microbiology with digester functionality may help to develop efficient, customized methanogenic cultures to enhance anaerobic bioprocesses. Preservation of methanogenic cultures via drying would be a cost-effective option for research and practical applications. However, preservation of methanogenic cultures is challenging due to methanogen sensitivity to O2 toxicity and drying, and very limited work is reported …

Relating Methanogen Community Structure And Function In Anaerobic Digesters, Benjamin T.W. Bocher

Dissertations (1934 -)

A deeper understanding of how microbial community structure relates to process function would help improve anaerobic digester design. This dissertation describes both qualitative and quantitative relationships between anaerobic digester function and microbial community structure. Community structure was characterized using banding pattern intensities from denaturing gradient gel electrophoresis (DGGE) for the mcrA gene of methanogenic Archaea. The first project compared a single-stage continuously mixed stirred tank reactor (CSTR) and staging with an acidogenic CSTR followed by a methanogenic CSTR. After seeding with the same biomass, these unique process configurations exhibited different function and qualitatively different methanogen communities. Compared to a single-stage …

Legacy Effects In Material Flux: Structural Catchment Changes Predate Long-Term Studies, Daniel J. Bain, Mark B. Green, John L. Campbell, John F. Chamblee, Sayo Chaoka, Jennifer M. Fraterrigo, Sujay S. Kaushal, Sherry L. Martin, Thomas E. Jordan, Anthony J. Parolari, William V. Sobczak, Donald E. Weller, Wilfred M. Wollheim, Emery R. Boose, Jonathan M. Duncan, Gretchen M. Gettel, Brian R. Hall, Praveen Kumar, Jonathan R. Thompson, James M. Vose, Emily M. Elliott, David S. Leigh

Civil and Environmental Engineering Faculty Research and Publications

Legacy effects of past land use and disturbance are increasingly recognized, yet consistent definitions of and criteria for defining them do not exist. To address this gap in biological- and ecosystem-assessment frameworks, we propose a general metric for evaluating potential legacy effects, which are computed by normalizing altered system function persistence with duration of disturbance. We also propose two distinct legacy-effect categories: signal effects from lags in transport and structural effects from physical landscape changes. Using flux records for water, sediment, nitrogen, and carbon from long-term study sites in the eastern United States from 1500 to 2000, we identify gaps …

Resonant Characteristics Of Rectangular Microcantilevers Vibrating Torsionally In Viscous Liquid Media, Tao Cai, Fabien Josse, Isabelle Dufour, Stephen M. Heinrich, Nicholas J. Nigro, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

The resonant characteristics of rectangular microcantilevers vibrating in the torsional mode in viscous liquid media are investigated. The hydrodynamic load (torque per unit length) on the vibrating beam due to the liquid was first determined using a finite element model. An analytical expression of the hydrodynamic function in terms of the Reynolds number and aspect ratio, h/b (with thickness, h, and width, b) was then obtained by fitting the numerical results. This allowed for the resonance frequency and quality factor to be investigated as functions of both beam geometry and medium properties. Moreover, the effects of the aspect ratio on …

Fertilization Effects On The Ecohydrology Of A Southern California Annual Grassland, Anthony J. Parolari, Michael L. Goulden, Rafael L. Bras

Civil and Environmental Engineering Faculty Research and Publications

Nitrogen limits leaf gas exchange, canopy development, and evapotranspiration in many ecosystems. In dryland ecosystems, it is unclear whether increased anthropogenic nitrogen inputs alter the widely recognized dominance of water and energy constraints on ecohydrology. We use observations from a factorial irrigation and fertilization experiment in a nitrogen-limited southern California annual grassland to explore this hypothesis. Our analysis shows growing season soil moisture and canopy-scale water vapor conductance are equivalent in control and fertilized plots. This consistency arises as fertilization-induced increases in leaf area index (LAI) are offset by reduced leaf area-based stomatal conductance, gs. We interpret this as evidence …

Detection And Analysis Of Sludge Bulking Events Using Data Mining And Machine Learning Approach, Yuanhao Zhao

Master's Theses (2009 -)

Sludge bulking is the most notable cause of activated sludge plant failure (i.e. exceeding discharge permit quality limits) worldwide. Numerous mathematical methods have been applied to detect and provide warning for the prevention of sludge bulking. However, these models often fail to reliably forecast sludge bulking events because they focus on the point-by-point "curve-fitting" strategy, while the number of bulking event data points is relatively small in comparison with the large amount of data in the time series. Therefore, three machine learning approaches which focus on detecting the temporal pattern data before the sludge bulking events are considered in this …

Measuring Bridge Construction Efficiency Using The Wireless Real-Time Video Monitoring System, Yong Bai, Jun Huan, Seonghoon Kim

Civil and Environmental Engineering Faculty Research and Publications

To enhance the efficiency of bridge construction, the wireless real-time video monitoring system (WRITE) was developed. Utilizing the advanced technologies of computer vision and artificial neural networks, the developed system first wirelessly acquired a sequence of images of work-face operations. Then human pose analyzing algorithms processed these images in real time to generate human poses associated with construction workers who performed the operations. Next, a portion of the human poses were manually classified into three categories as effective work, contributory work, and ineffective work and were used to train the built-in artificial neural networks (ANN). Finally, the trained neural networks …

Anaerobic Co-Digestion For Enhanced Renewable Energy And Green House Gas Emission Reduction, Navaneethan Navaratnam

Dissertations (1934 -)

The need to develop renewable energy is important for replacing fossil fuel, which is limited in quantity and also tends to increase in price over time. The addition of high strength organic wastes in municipal anaerobic digesters is growing and tends to increase renewable energy production. In addition, conversion of wastes to energy significantly reduces uncontrolled greenhouse gas emissions. Co-digestion of municipal sludge with any combination of wastes can result in synergistic, antagonistic or neutral outcomes. The objectives of this study were to identify potential co-digestates, determine synergistic, antagonistic and neutral effects, determine economic benefits, quantify performance of bench scale …

The Effect Of Thermal Hydrolysis Pretreatment On The Anaerobic Degradation Of Nonylphenol And Short-Chain Nonylphenol Ethoxylates In Digested Biosolids, Patrick J. Mcnamara, C. A. Wilson, M. T. Wogen, S. N. Murthy, J. T. Novak, Paige J. Novak

Civil and Environmental Engineering Faculty Research and Publications

The presence of micropollutants can be a concern for land application of biosolids. Of particular interest are nonylphenol diethoxylate (NP₂EO), nonylphenol monoethoxylate (NP₁EO), and nonylphenol (NP), collectively referred to as NPE, which accumulate in anaerobically digested biosolids and are subject to regulation based on the environmental risks associated with them. Because biosolids are a valuable nutrient resource, it is essential that we understand how various treatment processes impact the fate of NPE in biosolids. Thermal hydrolysis (TH) coupled with mesophilic anaerobic digestion (MAD) is an advanced digestion process that destroys pathogens in biosolids and increases methane …

Characteristics Of Laterally Vibrating Resonant Microcantilevers In Viscous Liquid Media, Russell Cox, Fabien Josse, Stephen M. Heinrich, Oliver Brand, Isabelle Dufour

Civil and Environmental Engineering Faculty Research and Publications

The characteristics of microcantilevers vibrating laterally in viscous liquid media are investigated and compared to those of similar microcantilevers vibrating in the out-of-plane direction. The hydrodynamic loading on the vibrating beam is first determined using a numerical model. A semi-analytical expression for the hydrodynamic forces in terms of the Reynolds number and the aspect ratio (beam thickness over beam width) is obtained by introducing a correction factor to Stokes’ solution for a vibrating plate of infinite area to account for the effects of the thickness. The results enable the effects of fluid damping and effective fluid mass on the resonant …

A Quantitative Study Of Robustness Characteristics In Steel Framed Structures, Christopher Herman Raebel

Dissertations (1934 -)

Robustness is a desirable property in any structural design. Robustness may be thought of as the building's inherent structural ability to resist loads other than those anticipated during design. Examples of unanticipated loads are damage to a column or beam due to impact; damage due to the concussion of a blast; strength reduction due to extreme heat during a fire; and localized accidental overload of a beam or column. Each of these events, although very different in their nature, has one major point in common; in each case the path of load resistance changes in a way that was not …

Tertiary-Treated Municipal Wastewater Is A Significant Point Source Of Antibiotic Resistance Genes Into Duluth-Superior Harbor, Patrick J. Mcnamara, Tucker R. Burch, Timothy M. Lapara, David T. Tan, Mi Yan, Jessica J. Eichmiller

Civil and Environmental Engineering Faculty Research and Publications

In this study, the impact of tertiary-treated municipal wastewater on the quantity of several antibiotic resistance determinants in Duluth-Superior Harbor was investigated by collecting surface water and sediment samples from 13 locations in Duluth-Superior Harbor, the St. Louis River, and Lake Superior. Quantitative PCR (qPCR) was used to target three different genes encoding resistance to tetracycline (tet(A), tet(X), and tet(W)), the gene encoding the integrase of class 1 integrons (intI1), and total bacterial abundance (16S rRNA genes) as well as total and human fecal contamination levels (16S rRNA genes specific to the genus Bacteroides …

Capturing The Lost Phosphorus, Bruce E. Rittmann, Brooke K. Mayer, Paul Westerhoff, Mark Edwards

Civil and Environmental Engineering Faculty Research and Publications

Minable phosphorus (P) reserves are being depleted and will need to be replaced by recovering P that currently is lost from the agricultural system, causing water-quality problems. The largest two flows of lost P are in agricultural runoff and erosion (∼46% of mined P globally) and animal wastes (∼40%). These flows are quite distinct. Runoff has a very high volumetric flow rate, but a low P concentration; animal wastes have low flow rates, but a high P concentration together with a high concentration of organic material. Recovering the lost P in animal wastes is technically and economically more tractable, and …

Resonant Microcantilevers For The Determination Of The Loss Modulus Of Thin Polymer Films, Cedric Ayela, Stephen M. Heinrich, Fabien Josse, Isabelle Dufour

Civil and Environmental Engineering Faculty Research and Publications

The increasing interest in polymer materials creates the need for accurate tools to characterize their mechanical properties. Due to energy dissipation in polymers during deformation, these materials exhibit viscoelastic behavior. Accurate determination of these viscoelastic properties and, more specifically, viscous losses, remains challenging and mainly unknown for thin polymer films. In this paper, a straightforward method to determine the loss modulus of organic materials using resonating microcantilevers has been developed. The extracted results for polyisobutylene show the variation of viscous losses over a large range of frequencies (7-350 kHz).

A Computationally Efficient Ground-Motion Selection Algorithm For Matching A Target Response Spectrum Mean And Variance, Nirmal Jayaram, Ting Lin, Jack W. Baker

Civil and Environmental Engineering Faculty Research and Publications

Dynamic structural analysis often requires the selection of input ground motions with a target mean response spectrum. The variance of the target response spectrum is usually ignored or accounted for in an ad hoc manner, which can bias the structural response estimates. This manuscript proposes a computationally efficient and theoretically consistent algorithm to select ground motions that match the target response spectrum mean and variance. The selection algorithm probabilistically generates multiple response spectra from a target distribution, and then selects recorded ground motions whose response spectra individually match the simulated response spectra. A greedy optimization technique further improves the match …

On The Relative Sensitivity Of Mass-Sensitive Chemical Microsensors, Luke A. Beardslee, S. Truax, J.-J. Su, Stephen M. Heinrich, Fabien Josse Phd, O. Brand

Civil and Environmental Engineering Faculty Research and Publications

In this work, the chemical sensitivity of mass-sensitive chemical microsensors with a uniform layer sandwich structure vibrating in their lateral or in-plane flexural modes is investigated. It is experimentally verified that the relative chemical sensitivity of such resonant microsensors is -to a first order- independent of the microstructure's in-plane dimensions and the flexural eigenmode used, and only depends on the layer thicknesses and densities as well as the sorption properties of the sensing film. Important implications for the design of mass-sensitive chemical microsensors are discussed, whereby the designer can focus on the layer stack to optimize the chemical sensitivity and …

Influence Of Non-Ideal Clamping In Microcantilever Resonant Frequency Estimation, L. Fadel-Taris, Cedric Ayela, Isabelle Dufour, Fabien Josse, Stephen M. Heinrich, D. Saya, O. Brand

Civil and Environmental Engineering Faculty Research and Publications

Among the most promising sensing platforms are resonating microcantilevers due to their high sensitivity and wide application range. A key parameter of the device implementation is the predicted value of the resonant frequency that depends on the modeling and considerations of relevant physical phenomena. In fact, the estimation based on the conventional, perfectly clamped, Bernoulli-Euler cantilever beam does not lead to satisfactory accuracy in certain cases. Hence this work investigates two system characteristics that may affect the re sonant frequency (a support effect and a so-called rim effect) and provides solutions for a straightforward estimation of rim dimension using resonance …

Damping And Mass Sensitivity Of Laterally Vibrating Resonant Microcantilevers In Viscous Liquid Media, Russell Cox, Jinjin Zhang, Fabien Josse, Stephen M. Heinrich, Isabelle Dufour, Luke A. Beardslee, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

The effect of liquid viscosity and density on the characteristics of laterally excited microcantilevers is investigated and compared to transversely excited microcantilevers. When immersed into a viscous liquid medium such as water from air, the resonant frequency of laterally (in-plane) vibrating microcantilevers is shown to decrease by only 5-10% as compared to ~50% reduction for transversely (out-of-plane) vibrating microcantilevers. Furthermore, as the viscosity of the medium increases the resonant frequency of a laterally vibrating beam is shown to decrease at a slower rate than that of a transversely vibrating beam. The decreased viscous damping also leads to increases in the …

Instrumentation Of Buildings To Enhance Student Learning - A Case Study At Marquette University's Discovery Learning Compex, Meredith Claeys

Master's Theses (2009 -)

The new engineering building at Marquette University, the Discovery Learning Complex, has been designed to change the way engineering education is delivered by using the building itself as a teaching tool for the next generation of engineers. The structural system for the building has been instrumented to allow students access to structural system data, wind speed data, and foundation pressures enabling this data from the building to be integrated into the teaching environment. The building also will display aspects of the building management system for public viewing. An array of weather stations will be installed on the roof, allowing the …

A Petri Net Simulation Model For Virtual Construction Of Earthmoving Operations, F. F. Cheng, Y. W. Wang, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

A common and extended Petri net simulation framework for virtual construction of earthmoving operations is developed to simulate dynamic changes of workflow and information flow in the earthmoving construction process and illustrate the constraint relationship between various operational equipment and construction restrictions. The proposed framework considers factors that influence earthmoving operations including randomness of construction activities, individual preference of equipment scheduling, and constraint relationship between equipment and construction environment. With the given equipment availability and project indirect cost, the framework can predict construction situation, equipment utilization rate, estimated duration and cost to achieve visualized and intelligent scheduling of virtual construction …

Modeling Of Cfrp-Concrete Interface Subjected To Coupled Pull-Out And Push-Off Actions, Tayyebeh Mohammadi, Baolin Wan, Jian-Guo Dai

Civil and Environmental Engineering Faculty Research and Publications

This paper presents a finite element (FE) modeling method for predicting the IC debonding failure when the FRP/concrete interface is subjected to coupled pull-out (shear) and push-off (dowel) actions. Damaged plasticity model was used to simulate the behavior of concrete close to FRP/concrete interface. A thin damage band exposed to mixed-mode loading condition was modeled separately along the FRP-concrete interface. Cohesive elements were used to model the FRP/concrete interface. A sensitivity analysis was performed to find the appropriate damaged band dimensions, bending stiffness of FRP, and tensile strength of concrete for the model. The numerical results were validated by the …

An Analytical Model Of A Thermally Excited Microcantilever Vibrating Laterally In A Viscous Fluid, Stephen M. Heinrich, Rabin Maharjan, Isabelle Dufour, Fabien Josse, Luke A. Beardslee, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

To achieve higher quality factors (Q) for microcantilevers used in liquid-phase sensing applications, recent studies have explored the use of the lateral (in-plane) flexural mode. In particular, we have recently shown that this mode may be excited electrothermally using integrated heating resistors near the micro cantilever support, and that the resulting increase in Q helps to make low-ppb limits of detection a possibility in liquids. However, because the use of electrothermally excited, liquid-phase, microcantilever-based sensors in lateral flexure is relatively new, theoretical models are lacking. Therefore, we present here a new analytical model for predicting the vibratory response of these …

Geometrical Optimization Of Resonant Cantilevers Vibrating In In-Plane Bending Modes, Luke A. Beardslee, Assim M. Addous, Kemal S. Demirci, Oliver Brand, Stephen M. Heinrich, Fabien Josse

Civil and Environmental Engineering Faculty Research and Publications

The influence of the beam geometry on the quality factor and resonance frequency of resonant silicon cantilever beams vibrating in their fundamental in-plane flexural mode has been investigated in air and water. Compared to cantilevers vibrating in their out-of-plane flexural mode, utilizing the in plane mode results in reduced damping and reduced mass loading by the surrounding fluid. Quality factors as high as 4,300 in air and 67 in water have been measured for cantilevers with a 12 μm thick silicon layer. This is in comparison to Q factors up to 1,500 in air and up to 20 in water …

Evaluation Of Runoff Response To Moving Rainstorms, Jin Liang

Dissertations (1934 -)

The primary hypothesis from the hydrological literature is that downstream moving storms with storm length (Ls) less than watershed length (Lc) magnify the peak discharges. This hypothesis was developed from the kinematic-wave modeling, and was evaluated in a plot between the dimensionless peak discharge and dimensionless storm velocity. Previously unpublished experimental data collected from the Watershed Experimentation System (WES), obtained from the late Professor Ben C. Yen at the University of Illinois at Urbana-Champaign, were used in comparison with the simulation results of the kinematic-wave model. It is found that downstream moving storms with Ls/Lc <1 increase the peak discharges to a limited extent compared to stationary storms, but the kinematic-wave model overstates the increase in the peak flows resulting from downstream moving storms with Ls/Lc <1. This difference between model projections and laboratory data was attributed to backwater effects in the experimental runoff.

To evaluate the importance of …

Risk-Based Seismic Design Optimization Of Steel Building Systems With Passive Damping Devices, Junshan Liu

Dissertations (1934 -)

Nonlinear time history analysis software and an optimization algorithm for automating design of steel frame buildings with and without supplemental passive damping systems using the risk- or performance-based seismic design philosophy are developed in this dissertation. The software package developed is suitable for conducting dynamic analysis of 2D steel framed structures modeled as shear buildings with linear/nonlinear viscous and viscoelastic dampers. Both single degree of freedom (SDOF) and multiple degree of freedom (multistory or MDOF) shear-building systems are considered to validate the nonlinear analysis engine developed. The response of both un-damped and damped structures using the 1940 EI Centro (Imperial …

Bioaugmentation For Recovery Of Anaerobic Digesters Subjected To Organic Overload, Vaibhav Panjabrao Tale

Dissertations (1934 -)

Anaerobic digester upset due to organic overload is common and methods to reduce recovery time would be beneficial. One potential method is bioaugmentation, the addition of an external culture for performance improvement. Methanogenic community structure differs from digester to digester and there may exist a relation between specific methanogenic activity (SMA) and microbial community composition. The research presented herein tested whether there is a relationship between SMA and community structure. Also, the effectiveness of bioaugmentation was tested by hypothesizing that bioaugmenting with a methanogenic, propionate-degrading culture acclimated to small oxygen doses will help rapid recovery of organically overloaded digesters.

Fourteen …

Performance Evaluation Of Open Graded Base Course With Doweled And Non-Doweled Transverse Joints, Robert Schmitt, Samuel Owusu-Ababio, James Crovetti

Transportation Reports with the Wisconsin Department of Transportation

The objectives of this study were to investigate the performance of 20-year old doweled/non-doweled and dense-graded/permeable base test sections on three concrete pavement segments in Wisconsin: USH 18/151 in Iowa and Dane counties, STH 29 in Brown County, and USH 151 in Columbia and Dane Counties. Five pavement bases were placed including: dense graded, asphalt-stabilized permeable, cement-stabilized permeable, and untreated permeable having two gradation sizes.

USH 18/151 test sections had similar performance (PDI) for doweled unsealed pavement on dense and permeable base. Distresses common to all segments included slight to moderate distressed joints/cracks and slight transverse faulting. Asphalt-stabilized permeable base …

Liquid-Phase Chemical Sensing Using Lateral Mode Resonant Cantilevers, Luke A. Beardslee, Kemal S. Demirci, Y. Luzinova, B. Mizaikoff, Stephen M. Heinrich, Fabien Josse, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

Liquid-phase operation of resonant cantilevers vibrating in an out-of-plane flexural mode has to date been limited by the considerable fluid damping and the resulting low quality factors (Q factors). To reduce fluid damping in liquids and to improve the detection limit for liquid-phase sensing applications, resonant cantilever transducers vibrating in their in-plane rather than their out-of-plane flexural resonant mode have been fabricated and shown to have Q factors up to 67 in water (up to 4300 in air). In the present work, resonant cantilevers, thermally excited in an in-plane flexural mode, are investigated and applied as sensors for volatile …

Passenger Car Equivalent Factors For Level Freeway Segments Operating Under Moderate And Congested Conditions, Umama Ahmed

Master's Theses (2009 -)

The significant impact Heavy Vehicles (HV) have on freeway operations has been identified since the first edition of the Highway Capacity Manual (HCM). The method of incorporating their impact in freeway capacity calculations has changed through the years. The HCM 2000 used Passenger Car Equivalent (PCE) values and percent of trucks/buses and Recreational Vehicles (RV) to account for HV effect on capacity. However PCE values in the most recent HCM edition rely on a limited field database and extensive simulation runs based on this information; they were calibrated on `steady-flow' traffic operations. The objective of this effort was to indentify …