Engineering Commons^™

Observations Of Peak Strength Behavior In Csa Cement Mortars, Joshua V. Brien, Kevin R. Henke, Kamyar C. Mahboub

Civil Engineering Faculty Publications

The purpose of this study was to assess the mechanical property performance behavior of calcium sulfoaluminate (CSA) cement mortar when cured at ambient laboratory temperature of ~23°C (73°F) and constant 50% relative humidity for an extended period of time. Four CSA cement mortars were tested. Three CSA cement mortars contained equivalent mass amounts of calcium sulfate; whereas, the fourth mortar contained double the amount of calcium sulfate. The three CSA cement mortars containing constant mass amounts of calcium sulfate differed as the specific type of calcium sulfate varied across the three formulations—one mortar containing solely anhydrite, one mortar contained half …

Effects Of Hinged Dowel System On The Performance Of Concrete Pavement Joints, Alireza Zeinali, Kamyar C. Mahboub, Herbert F. Southgate

Civil Engineering Faculty Publications

Concrete joint failure is a major distress mode in rigid pavements. Improving the joint performance in concrete pavements could yield substantial savings in terms of reduced maintenance and rehabilitation costs. The newly developed Hinged Dowel System (HDS) is a means for transferring loads across the concrete pavement joints. The HDS was patented as a new invention by the United States Patent and Trademark Office, and it is envisioned that it could significantly reduce the potential for joint failure in concrete pavements. The HDS assembly comprises a number of dowel bars and a collective hinge provided at the mid-length of the …

Heating Effects Through Harmonic Distortion On Electric Cables In The Built Environment, Kevin O'Connell

Doctoral

Under ideal circumstances, electric power supply voltage and current waveforms should be sinusoidal. However, this is very seldom the case in the built environment, due to the proliferation of non-linear loads. Examples of non-linear loads are those containing switched mode power supplies, reactors and electronic rectifiers/inverters. Common devices such as personal computers, fluorescent lighting, electric motors, variable speed drives, transformers and reactors and virtually all other electronic equipment are examples of non-linear loads. Non-linear loads are the norm in the built environment rather than the exception. Such loads produce complex current and voltage waves and simple spectral analysis of these …

Field Evaluation Of Arbuscular Mycorrhizal Fungal Colonization In Bacillus Thuringiensis Toxin-Expressing (Bt) And Non-Bt Maize, Tanya E. Cheeke, Mitchell B. Cruzan, Todd N. Rosenstiel

Biology Faculty Publications and Presentations

The cultivation of genetically engineered Bacillus thuringiensis toxin-expressing (Bt) maize continues to increase worldwide, yet the effects of Bt crops on arbuscular mycorrhizal fungi (AMF) in soil are poorly understood. In this field experiment, we investigated the impact of seven different genotypes of Bt maize and five corresponding non-Bt parental cultivars on AMF and evaluated plant growth responses at three different physiological time points. Plants were harvested 60 days (active growth), 90 days (tasseling and starting to produce ears), and 130 days (maturity) after sowing, and data on plant growth responses and percent AMF colonization of roots at each harvest …

Zein: Novel Natural Polymer For Nanoparticle- And Film-Mediated Gene Delivery, Jessica D. Taylor

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Gene delivery, the introduction of DNA into cells, is applicable to gene therapy, DNA vaccination, functional genomics and diagnostics, tissue engineering, and drug-eluting medical devices. Particulates incorporating DNA are promising vehicles for gene delivery and overcome some of the barriers that hinder successful gene transfer, with the ability to protect DNA and provide for controlled, localized, and sustained release and transfection. Furthermore, innovative new gene delivery strategies that incorporate DNA particulates or complexes within films or coatings for devices and scaffolds could further provide for controlled and sustained transfection at the site of implant. Zein, a hydrophobic protein from corn, …

Quantifying The Impact Of Boreal Forest Fires On Tropospheric Oxidants Over The Atlantic Using Aircraft And Satellites (Bortas) Experiment: Design, Execution And Science Overview, P. I. Palmer, M. Parrington, J. D. Lee, A. C. Lewis, A. R. Rickard, P. F. Bernath, T. J. Duck, D. L. Waugh, D. W. Tarasick, R. C. Owen, Et. Al.

Michigan Tech Publications, Part 1

We describe the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of air masses that contain the emission products from seasonal boreal wildfires and how these air masses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada, based out of Halifax, Nova Scotia. Atmospheric ground-based and sonde measurements over Canada and the Azores associated with the planned …

Dynamic Modeling Of A Belt Driven Electromechanical Xy Plotter Cutter, Joseph V. Prisco

Master's Theses (2009 -)

Current industrial XY plotter cutters that use a belt driven gantry for the X motion and media feed for the Y motion sometimes have performance issues in cutting out high quality shapes. Mathematical models for these plotter cutters are not publicly available and thus the parameters critical to cut quality are not well understood. This thesis develops a dynamic, electromechanical model for the gantry arm and media feed using first principles and a non-linear friction model. These models are independently simulated and experimentally verified. In order to verify the effectiveness of the individual models, they are combined with a control …

The Effects Of Separating Visual And Motor Workspaces On The Generalization Of Visuomotor Adaptation Across Movement Conditions, Yuming Lei

Master's Theses (2009 -)

Separating visual and proprioceptive information in terms of workspace locations during reaching movement has been shown to disturb transfer of visuomotor adaptation across the arms. Here, we investigated whether separating visual and motor workspaces would also disturb generalization of visuomotor adaptation across movement conditions within the same arm. In our behavioral study, subjects were divided into four experimental groups (plus three control groups). The first two groups adapted to a visual rotation under a "dissociation" condition in which the targets for reaching movement were presented in midline while their arm performed reaching movement laterally. Following that, they were tested in …

Simulation Of Power Control Of A Wind Turbine Permanent Magnet Synchronous Generator System, Nantao Huang

Master's Theses (2009 -)

This thesis presents a control system for a 2MW direct-drive permanent magnet synchronous generator wind turbine system with the objectives to capture the optimal power from the wind and ensure a maximum efficiency for this system. Moreover, in order to eliminate the electrical speed sensor mounted on the rotor shaft of the PMSG to reduce the system hardware complexity and improve the reliability of the system, a sliding mode observer based PM rotor position and speed sensorless control algorithm is presented here.

The mathematical models for the wind turbine and the permanent magnet synchronous machine are first given in this …

Chemically Sensitive Polymer Coatings For Sh-Surface Acoustic Wave Sensors For The Detection Of Benzene In Water, Robert Lenisa

Master's Theses (2009 -)

Polymer-coated shear horizontal surface acoustic wave (SH-SAW) sensors are investigated for the detection of benzene in aqueous samples. The SH-SAW sensors using three-layer geometry have a single polymer sensing layer which absorbs the analyte and interacts with the surface wave. Several polymers are identified as potential improvements over current sensing films based on glass transition temperature and Hildebrand solubility parameter. The polymers investigated in this work include poly (methyl acrylate) (PMA), poly (butyl acrylate) (PBA), poly (ethylene co-vinyl acetate) (PEVA), bisphenol-A poly (dimethylsiloxane) (BPA PDMS), and bisphenol-A poly (hexamethyltrisiloxane) (BPA HMTS).

The polymers are spin coated on a lithium tantalate …

Investigating The Possible Sources Of Error Using The Method Of Moments To Solve A Dielectric Scattering Problem, Phillip D. Bishop

Master's Theses (2009 -)

In an electromagnetic scattering problem, an incoming electromagnetic wave interacts with an object. The object is typically located in some medium, such as free space. When this electromagnetic wave becomes incident upon the object, the wave scatters. The goal of this work is to analyze the scattered fields for three different incoming wave types: a plane wave, a monopole line source, and a multipole line source. Each source is incident on an infinitely long circular cylinder of lossless dielectric material. Each source has a unique scattering characteristic.

The volume equivalence principle is used to replace the object geometry with mathematically …

An Fmri Study On Supra-Spinal Contributions To Upper And Lower Limb Motor Control, Shancheng Bao

Master's Theses (2009 -)

The differences in the neural mechanisms contributing to upper and lower extremity movement have not been fully elucidated, and this might be a factor that leads to the ineffectiveness of rehabilitation techniques for most stroke survivors. It is unclear whether therapies designed for upper extremities should also be used for the lower extremities, and vice versa. In this study, fMRI was used to examine the supraspinal control of UE and LE movement in both neurologically intact individuals and people with post-stroke hemiparesis. We compared the location, volume, and intensity of brain activity associated with upper and lower extremity pedaling and …

Flame Temperature Imaging Of A Low Nox Burner Via Laser Rayleigh Scattering, Nicholas A. Smith

Master's Theses (2009 -)

Federal and global legislation are requiring increasingly stringent emission regulation on household appliances and in particular water heater burners. Emissions like NOx (NO and NO2) are a growing concern due to their adverse health effects and contribution to tropospheric ozone, acid rain, and smog formation. As NOx is more closely controlled, appliance manufacturers are developing low emission burners for use in water heaters.

Flame temperature is strongly correlated to NOx production. Hence, characterizing flame temperatures in new burners is a key part of improving upon burners used today and the development of future burners. Temperature measurements applied to a new, …

Miniature, High Efficiency Transducers For Use In Ultrasonic Flow Meters, Meghna Saikia

Master's Theses (2009 -)

This thesis is concerned with the development of a new type of miniature, high efficiency transducer for use in ultrasonic flow meters. The proposed transducer consists of a thin plate of a suitable piezoelectric material on which an inter-digital transducer is fabricated for the generation and detection of plate acoustic waves. When immersed in a fluid medium, this device can convert energy from plate acoustic waves (PAWs) into bulk acoustic waves (BAWs) and vice versa. It is shown that this mode coupling principle can be used to realize efficient transducers for use in ultrasonic flow meters. This transducer can be …

Complementarities Of Probabilistic And Evidence Approaches: An Uncertainty Assessment For Selection Of Composite Material, Stella B. Bondi, Resit Unal, Patrick T. Hester, Trina M. Chytka

Engineering Technology Faculty Publications

A complimentary probabilistic and evidence theory approach is utilized to enhance uncertainty assessments in the area of critical safety characteristics for conceptual design. This research provides additional exploration into the failure modes necessary to utilize Fiber Reinforced Polymer (FRP) and various composites to their fullest potential and to minimize uncertainty by comparing probability and evidence theories. This combined approach has been applied to a selection of composite material that could provide uncertainty assessment design for a space transportation system. Uncertainty estimates presented are bounded by belief and plausibility functions. The results may provide additional information to the decision makers in …

Plastic Response Of Dislocation Glide In Solid Helium Under Dc Strain-Rate Loading, Caizhi Zhou, Jungjung Su, Matthias J. Graf, Charles J. Olson Reichhardt, Alexander V. Balatsky, Irene J. Beyerlein

Materials Science and Engineering Faculty Research & Creative Works

We develop a model for the gliding of dislocations and plasticity in solid ⁴He. This model takes into account the Peierls barrier, multiplication and interaction of dislocations, as well as classical thermally and mechanically activated processes leading to dislocation glide. We specifically examine the dc stress-strain curve and how it is affected by temperature, strain rate, and dislocation density. As a function of temperature and shear strain, we observe plastic deformation and discuss how this may be related to the experimental observation of elastic anomalies in solid hcp ⁴He that have been discussed in connection with the possibility …

Fixed Final Time Optimal Adaptive Control Of Linear Discrete-Time Systems In Input-Output Form, Qiming Zhao, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the fixed final time adaptive optimal regulation of discrete-time linear systems with unknown system dynamics is addressed. First, by transforming the linear systems into the input/output form, the adaptive optimal control design depends only on the measured outputs and past inputs instead of state measurements. Next, due to the time-varying nature of finite-horizon, a novel online adaptive estimator is proposed by utilizing an online approximator to relax the requirement on the system dynamics. An additional error term corresponding to the terminal constraint is defined and minimized overtime. No policy/value iteration is performed by the novel parameter update …

Improving Affordability: Separating Research From Development And From Design In Complex Programs, Bohdan W. Oppenheim

Systems Engineering Faculty Works

This paper presents arguments for why defense programs creating physical systems should clearly separate three developmental phases from each other: research, development and design. Research is to be performed first by small teams of scientists addressing the "unknown unknowns" and maturing fundamental science from TRL of 1 to about 3. Next, development of physical modules is to be performed by small and highly specialized engineers. Finally, the system-level design should focus on efficient trading off the module locations, sizes and shapes versus system performance, mass, power requirements, etc. The design with all modules mature and available is equivalent to a …

The Effect Of The Probiotic Pediococcus Acidilactici On The Gut Microbiota Ecology Of Rainbow Trout (Oncorhynchus Mykiss Walbaum) Analysed Using Dgge, Alice Anderson

The Plymouth Student Scientist

The microbiota of the gastrointestinal tract heavily influences the health, growth and survival of fish. Probiotics have proved effective in improving fish productivity in aquaculture. Research suggests that probiotics, supplemented in the feed, may elicit these benefits by altering the ecology of the gastrointestinal microbiota. The probiotic Pediococcus acidilactici has been successfully used for terrestrial animals and humans but its use in aquatic organisms has been less researched. In the present study, rainbow trout Oncorhynchus mykiss (Walbaum) were fed a diet that contained Ped. Acidilactici, or a control diet. Analysis of the posterior digesta bacteria, using a non-culture dependant technique, …

Osmotic Regulation Of The Amphipod Gammarus Chevreuxi (Sexton, 1912), Sam Houston

The Plymouth Student Scientist

This study investigated osmotic regulation in the amphipod, Gammarus chevreuxi, and is the first publication of this organism’s osmotic regulatory curves. Unlike most estuarine amphipods studied to date which are hyperosmotic regulators, G. chevreuxi is a hyper-hyposmotic regulator. The hyperosmotic gradient maintained by G. chevreuxi in dilute media is very low (~120mmol.L-1), which has been interpreted as evidence of freshwater ancestry among the Crustacea. Salinity acclimation did not appear to affect heart rate or pleopod beat frequency. The gill cells responsible for ion uptake appeared to be smaller in high salinities or distorted. The apical membrane in concentrated media shows …

Triclosan Enriches For Dehalococcoides-Like Chloroflexi In Anaerobic Soil At Environmentally Relevant Concentrations, Patrick J. Mcnamara, Mark J. Krzmarzick

Civil and Environmental Engineering Faculty Research and Publications

Triclosan is an antimicrobial agent that is discharged to soils with land-applied wastewater biosolids, is persistent under anaerobic conditions, and yet its impact on anaerobic microbial communities in soils is largely unknown. We hypothesized that triclosan enriches for Dehalococcoides-like Chloroflexi because these bacteria respire organochlorides and are likely less sensitive, relative to other bacteria, to the antimicrobial effects of triclosan. Triplicate anaerobic soil microcosms were seeded with agricultural soil, which was not previously exposed to triclosan, and were amended with 1 mg kg⁻¹ of triclosan. Triplicate control microcosms did not receive triclosan, and the experiment was run for …

Resonant Characteristics Of Rectangular Hammerhead Microcantilevers Vibrating Laterally In Viscous Liquid Media, Jinjin Zhang, Fabien Josse, Stephen M. Heinrich, Nicholas J. Nigro, Isabelle Dufour, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

The resonant characteristics of laterally vibrating rectangular hammerhead microcantilevers in viscous liquid media are investigated. The rectangular hammerhead microcantilever is modeled as an Euler-Bernoulli beam (stem) and a rigid body (head). A modified semi-analytical expression for the hydrodynamic function in terms of the Reynolds number, Re, and aspect ratio, h/b, is proposed to rapidly evaluate the sensing characteristics. Using this expression, the resonance frequency, quality factor and normalized surface mass sensitivity are investigated as a function of the dimensions of the microcantilever and liquid properties. Guidelines for design of hammerhead microcantilever geometry are proposed to achieve efficient sensing platforms for …

Bs News July/August

Building Services Engineering

No abstract provided.

Continuous Modulations Of Femtosecond Laserinduced Periodic Surface Structures And Scanned Line-Widths On Silicon By Polarization Changes, Weina Han, Lan Jiang, Xiaowei Li, Pengjun Liu, Le Xu, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Large-area, uniform laser-induced periodic surface structures (LIPSS) are of wide potential industry applications. The continuity and processing precision of LIPSS are mainly determined by the scanning intervals of adjacent scanning lines. Therefore, continuous modulations of LIPSS and scanned line-widths within one laser scanning pass are of great significance. This study proposes that by varying the laser (800 nm, 50 fs, 1 kHz) polarization direction, LIPSS and the scanned line-widths on a silicon (111) surface can be continuously modulated with high precision. It shows that the scanned line-width reaches the maximum when the polarization direction is perpendicular to the scanning direction. …

Nanowell-Trapped Charged Ligand-Bearing Nanoparticle Surfaces – A Novel Method Of Enhancing Flow-Resistant Cell Adhesion, Phat L. Tran, Jessica R. Gamboa, Katherine E. Mccracken, Mark R. Riley, Marvin J. Slepian, Jeong-Yeal Yoon

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Assuring cell adhesion to an underlying biomaterial surface is vital in implant device design and tissue engineering, particularly under circumstances where cells are subjected to potential detachment from overriding fl uid fl ow. Cell–substrate adhesion is a highly regulated process involving the interplay of mechanical properties, surface topographic features, electrostatic charge, and biochemical mechanisms. At the nanoscale level, the physical properties of the underlying substrate are of particular importance in cell adhesion. Conventionally, natural, pro-adhesive, and often thrombogenic, protein biomaterials are frequently utilized to facilitate adhesion. In the present study, nanofabrication techniques are utilized to enhance the biological functionality of …

Impact Of Measurement Scale On Infiltration And Phosphorus Leaching In Ozark Floodplains, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Brian E. Haggard, Chad J. Penn, Todd Halihan

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Increased nutrient loads have resulted in several adverse impacts on surface water quality, including excessive algal growth, fish kills, and drinking water taste and odor issues across the United States and especially in the Ozark ecoregion of northeastern Oklahoma and northwestern Arkansas. The significance of this problem has been highlighted by litigation, with one case even reaching the U.S. Supreme Court (Arkansas et al. v. Oklahoma et al., 503 U.S. 91) which required the upstream state to meet downstream water quality standards. The overarching objective of this line of research was to characterize phosphorus leaching to alluvial aquifers in the …

Finite Element Modeling Of Phosphorus Leaching Through Floodplain Soils Dominated By Preferential Flow Pathways, Ryan P. Freiberger, Derek M. Heeren, Garey A. Fox

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Phosphorus is a critical nutrient in soils, providing both positive and negative effects to different systems. While optimum crop growth requires a range of P above 0.2 mg/L, preventing surface water enrichment generally requires P to be below 0.03 mg/L. Proper application and control of phosphorus is important to increase farming efficiency and to protect freshwater systems from toxic algal growth. While the movement of phosphorus through many soil types has been well-documented, the presence of highly conductive, gravel outcrops and macropores in soil can have a significant, poorly-documented effect on phosphorus movement. In the Ozark ecoregion, for example, the …

Application Of Isothermal Calorimetry To The Study Of Phosphorus Sorption Onto Soils In A Flow-Through System, Chad J. Penn, Derek M. Heeren, Garey A. Fox

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The degree, mechanisms, and kinetics of phosphorus (P) sorption onto soils can have a significant influence on leaching losses of P from soil. The objectives of this study were to measure the impact of retention time (RT) on P sorption in a flow-through system intended to simulate downward movement of a P solution through two different riparian soils, and determine if isothermal titration calorimetry (ITC) can provide useful information reflective of flow-through results. Topsoil from two riparian/alluvial soils was sampled and characterized for P concentrations and parameters related to P sorption. Flow-through P sorption experiments were conducted in order to …

A Morphological Analysis Of A Hybrid Swarm Of Native Ulmus Rubra And Introduced U. Pumila (Ulmaceae) In Southeastern Nebraska, Christian Elowsky, Ingrid E. Jordon-Thaden, Robert B. Kaul

Nebraska Center for Biotechnology: Faculty and Staff Publications

The parental species and hybrid swarm of native Ulmus rubra Muhl. and the introduced, naturalized and weedy U. pumila L. were investigated in a 65-km transect in Lancaster, Saunders, and Butler counties in Nebraska. Thirty-two trees of U. rubra, 32 of U. pumila, and 50 of the hybrid swarm were sampled for leaves and buds and subsampled for flowers and fruits. Leaves were measured for petiole length, blade length, width, primary and secondary teeth per cm, number of secondary teeth per primary tooth, and texture. Buds were scored for color and distribution of trichomes. Flowers were sampled for stamen counts …

Narrow Grass Hedge Effects On Nutrient Transport Following Swine Slurry Application, John E. Gilley, Shannon L. Bartelt-Hunt, Seth J. Lamb, Xu Li, David B. Marx, Daniel D. Snow, David B. Parker, Brian L. Woodbury

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The effectiveness of a narrow grass hedge in reducing runoff nutrient loads following swine slurry application was examined. Slurry was applied to 0.75 m wide by 4.0 m long plots established on an Aksarben silty clay loam soil located in southeast Nebraska. Manure treatments consisted of no manure application and manure application to meet the 1, 2, or 3 year nitrogen (N) requirements for corn. Runoff water quality was measured during three 30 min simulated rainfall events. The grass hedge did not significantly reduce runoff nutrient transport after the swine slurry, which contained relatively small amounts of manure, was applied. …