Engineering Commons^™

Ls-Dyna® Modeling Enhancement Support, John D. Reid, Robert W. Bielenberg, Chaz Ginger

Nebraska Department of Transportation: Research Reports

The Pooled Fund Program member states provided funding for LS-DYNA modeling enhancements in Years 17 thru 22 (2006-2011), with a project period of 2006-2016. This report documents many of the modeling issues addressed throughout the project period. The funding has been effectively utilized to advance the current state-of-the-art for computer simulation and has provided the following benefits for the entire industry: (1) improved roadside safety hardware, (2) reduced development time and cost, (3) improved understanding of the behavior of roadside safety features, especially for impacts outside of normal crash test conditions, (4) improved LS-DYNA modeling techniques and procedures, and (5) …

A Novel Biochamberfor Modeling Of Atherosclerotic Arteries: In Vitro Capabilities And Applications, Iman Salafian, Angelos Karagiannis, Benjamin S. Terry, Yiannis S. Chatzizisis

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Atherosclerosis is a chronic disease that involves the lipid accumulation and inflammation of the arterial wall [1,2]. Despite great efforts,its pathophysiology has not been fully elucidated. Existent drugs can reduce its progression but there are no available drugs to prevent its complications [3,4]. Atherosclerosis remains the leading global cause of death[5].

The purpose of this work is to design and build a customized biochamber which can be used for the following studies:

•Study the pathophysiology of atherosclerosis in vitro & ex vivo

•Investigate the mechanisms of atherosclerotic plaque disruption

•Examine the direct effect of different anti-atherosclerotic drugs on lesions

•Use …

Chemical And Physical Priming Of Human Mesenchymal Stem Cells To Alter Nonviral Gene Delivery Outcomes, Tyler Kozisek, Andrew Hamann, Amy Mantz, Mathias Schubert, Eva Schubert, Angela K. Pannier

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

Human Mesenchymal Stem Cells: Human mesenchymal stem cells (hMSCs) are a multipotent cell, meaning they are able to differentiate into a more mature cell type, such as osteocytes, chondrocytes, and adipocytes, that are found in numerous tissues in the human body, such as bone marrow, fat, and muscle. Since hMSCs can be derived from adult human tissues, they do not have the same ethical concern associated with them as other stem cells, such as embryonic stem cells. Due to hMSCs multipotency and ease of obtaining, they have become one of the most widely researched stem cell types in areas such …

Project Halon: Engaging Secondary Students In High-Altitude Ballooning Experiments, James M. Taylor Jr., Derrick A. Nero

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Project HALON Overview

•Fewer US STEM graduates

•Shortage of STEM educators

•Lack of engaging, high quality STEM material in the classroom

•Potentially results in lower global economic competitiveness

Experiment Constraints

•Project brings together STEM major mentors and educators

•Builds understanding of research and operational challenges

•Students get excited about more complex experiments (CubeSATs)

HALON: High Altitude Learning Over Nebraska

•High altitude balloon lift platform

•Student-designed experiments tailored to student team abilities

•NASA-inspired near-space systems engineering process for tradeoffs

•Engagement / mentoring for pre-service and in-service educators

Department Of Biological Systems Engineering Newsletter, Spring 2017

BSE Department Magazine

No abstract provided.

Repair And Regeneration Of Chondral Defects: An In Vitro Study Demonstrating Feasibility And Mechanism Under Low Intensity Ultrasound, Neety Sahu, Anuradha Subramanian

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Holistic repair of damaged cartilage remains an unsolved biomedical problem. Current methods that employ microfracture (MF) or autologous chondrocyte implantation (ACT) or tissue engineered strategies yield inferior repaired cartilage (Fig. 1). Lack of chondroinductive factors at the site of injury, in vivo, has been identified as a factor that limits repair. Clinically amenable strategies that can improve repair are desired. A novel clinically translatable repair strategy based on low-intensity-ultrasound (US) is proposed (Fig.2). Differently from all approaches that use US, our approach employs US at the cell resonant frequency where bioeffects are maximized. We have shown that US impacts the …

Program And Proceedings: Nebraska Academy Of Sciences 1880–2017, 137th Anniversary Year, One Hundred-Twenty-Seventh Annual Meeting

Nebraska Academy of Sciences: Programs and Proceedings

Program

Aeronautics and Space Science

Chemistry and Physics

Collegiate Academy: Biology

Collegiate Academy: Chemistry and Physics

Biological and Medical Sciences

Aeronautics and Space Science: Poster Session

Applied Science and Technology

Maiben Memorial Lecture

Anthropology

Earth Science

Applied Science and Technology

Teaching of Science and Mathematics

Environmental Sciences

Friend of Science Award: Kacie Baum and Todd Young

In-Vehicle Evaluation Of Rumble Strips In Pre-And Post-Chip Sealed Maintenance Periods, Ernest Tufuor, Laurence Rilett

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Chip sealing will reduce the depth of rumble strips (RS) by approximately 1/8".  Will this depth reduction affect RS functional characteristics (audible and tactile warnings)?

There is no detailed study on the effectiveness of RS that have been chip sealed. USEFULNESS The results will be useful to the Nebraska Department of Roads to determine:

Operations: Whether RS will need to be re-milled after chip sealing. Cost & safety implications.

Design: New RS guidelines for highways expected to be chip sealed in the future.

It can be shown that a 1/8" reduction in the current milled RS design depth, as …

Primary Blast Waves Induced Brain Dynamics Influenced By Head Orientations, Yi Hua, Yugang Wang, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

There is controversy regarding the directional dependence of head responses subjected to blast loading. The goal of this work is to characterize the role of head orientation in the mechanics of blast wave-head interactions as well as the load transmitting to the brain. A three-dimensional human head model with anatomical details was reconstructed from computed tomography images. Three different head orientations with respect to the oncoming blast wave, i.e., front-on with head facing blast, back-on with head facing away from blast, and side-on with right side exposed to blast, were considered. The reflected pressure at the blast wave-head interface positively …

Evaluation Of Tack Coating Practices For Asphalt Overlays In Nebraska, Soroosh Amelian, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

The strength of the bond between asphalt layers affects the lifespan of pavement structures. It is also a key factor in preventing major pavement distresses, such as slippage cracking and delamination. This research project evaluates and compares the effectiveness and performance of different tack coating approaches to ensure the proper bond strength is achieved in asphalt concrete (AC) interlayers through an experimental study. Various tack coat materials, including different types of emulsified asphalt and asphalt binders, at multiple application rates and dilution ratios were investigated. In the first part of this study, laboratory-prepared samples were used to evaluate the sensitivity …

Superpositioning High Power Lasers For Mid-Air Image Formations, Auston Viotto

UCARE: Research Products

This research evaluates different methods to create voxels, 3-dimensional pixels, in air without the need for special glasses or reflections off of surfaces. Research on the advantages of superimposing or the culmination, focusing, of laser light will be conducted. The point of superpositioning/culmination will be evaluated by the brightness of the voxel due to the Rayleigh Scatter Effect. The voxel’s brightness is dependent on the laser output strength and inversely proportional to its wavelength. Once a superimposed/culminated voxel has been created in the lab the next step will be to manipulate the location of the voxel through 3-dimensional space. This …

How Tonality And Loudness Of Noise Relate To Annoyance And Task Performance” Noise Control Eng. J. 65(2), 71-82., Joonhee Lee, Jennifer M. Francis, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Audible tones in noise generated by building mechanical equipment can be a leading cause of complaints from occupants. A number of metrics have been developed to quantify prominence of a tone, but previous work has shown that the impact of a certain tonality appears to vary with the level of the broadband noise signal. More work on how tonal signals of varying tonality, tone frequency and broadband noise levels relate to annoyance and task performance is needed. This paper investigates such relationships between current noise metrics, annoyance and task performance under assorted tonal noise conditions through subjective testing. Participants rated …

Energy–Water Reduction And Wastewater Reclamation In A Fluid Milk Processing Facility, Carly Rain Adams, Yulie E. Meneses, Bing Wang, Curtis L. Weller

Department of Food Science and Technology: Dissertations, Theses, and Student Research

The energy-water nexus is the inseparable connection linking water and energy. We are faced with a unique opportunity to co-manage these resources, as conservation of one is directly linked to the conservation of its counterpart. Therefore, immediately facing this critical challenge, will lead to tangible impacts on the water and energy crisis our food system is faced with. Determining the role of water and energy in the food industry has proved to be the starting point for reducing the distance between process productivity and resource efficiency. Therefore, this research focuses on determining opportunities for water-energy optimization and wastewater reduction and …

Investigation Of Petroleum Use In Off-Road Agricultural Machinery And Analysis Of J1939 Controller Area Network (Can) Data For Advanced Machinery Testing, Rodney Rohrer

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

Nearly all modern off-road agricultural machinery are powered by petroleum, primarily diesel fuel. Equipment manufacturers work to improve fuel efficiency of their equipment to provide better value to their customers. Benefits of reducing petroleum use include lower operating costs, improved operational efficiency, improved energy security, and environmental benefits. Agricultural tractor testing focuses primarily on characterizing maximum performance but there is a need for advanced test procedures to better measure fuel efficiency for load cases representative of in-field operations. This would help farmers make better equipment purchasing and utilization decisions and help manufacturers quantify efficiency improvements; ultimately driving continued progress toward …

High Throughput In Vivo Analysis Of Plant Leaf Chemical Properties Using Hyperspectral Imaging, Piyush Pandey, Yufeng Ge, Vincent Stoerger, James C. Schnable

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

The possibility of predicting plant leaf chemical properties using hyperspectral images was studied. Sixty maize and 60 soybean plants were used, and two experiments were conducted: one with water limitation and the second with nutrient limitation, with the purpose of creating wide ranges of these chemical properties in plant leaf tissues. A hyperspectral imaging system with a spectral range from 550 to 1700 nm was used to acquire plant images in a high throughput fashion (plants placed on an automated conveyor belt). Leaf chemical properties were measured in the laboratory. Partial least squares regression was implemented on spectral data to …

Genetic Code Expansion In Biochemical Investigations And Biomedical Applications, Nanxi Wang

Department of Chemistry: Dissertations, Theses, and Student Research

Genetic code expansion provides a powerful tool for site-specific incorporation of unnatural amino acids (unAAs) with novel biochemical and physiological properties into proteins in live cells and organisms. To achieve this, a nonsense codon suppression system, which consists of an orthogonal aminoacyl-tRNA synthetase (aaRS) and tRNA pair that specifically decodes a nonsense codon (e.g., amber codon and quadruplet codon) with an unAA but do not “cross talk” with their endogenous counterparts, was established. This Ph.D. thesis presents our efforts on evolution and application of nonsense codon suppression systems for biochemical and biomedical investigations.

In Chapter 1, a brief overview of …

Physiologically-Aware Communication Architecture For Transmission Of Biomedical Signals In Basns For Emerging Iot Applications, Jose Santos, Dongming Peng, Hamid Sharif

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

This research work proposes a novel physiologicallyaware communication architecture for the transmission of biomedical signals in BASNs (Body Area Sensor Networks) and wearables for emerging IoT applications. The architecture to fulfill the following objectives:

• Reduce volume of biomedical data in IoT networks and Internet infrastructure.

• Minimize the required computational load of biomedical data on the cloud side.

• Extend the lifetime of the mobile wearable/BASN through improved energy savings.

This architecture is generalizable to class of biomedical signals. It prevents large volume of biomedical data to be generated; uses patient state to control almost any system parameter; achieves …

Reducing Graphene–Metal Contact Resistance Via Laser Nano-Welding, Kamran Keramatnejad, H. Rabiee Golgir, Y. S. Zhou, D. W. Li, X. Huang, Yongfeng Lu

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The large graphene-metal contact resistance is a major limitation for development of graphene electronics. graphene behaves as an insulator for out-of-plane carrier transport to metallic contacts.

Laser nano-welding was developed and led to RC reductions of up to 84%.

Localized laser irradiation at the edges of graphene led to the formation of chemically active point defects.

Precise structural modifications and formation of G-M bonding led to improved carrier efficiency in graphene devices.

Chitosan Nanoparticle Modifications For Improved Gene Delivery In An Oral Dna Vaccine Application, Austin Helmink

Honors Program: Senior Projects (Public)

Vaccines represent one of the most significant medical innovations of the 20^th century, resulting in the eradication or near eradication of a handful of deadly diseases. However, many infectious diseases remain resistant to effective vaccination, largely due to a lack full immune activation by traditional protein-based vaccines. A promising alternative vaccination strategy is the emerging development of DNA vaccines, which rely upon the delivery of exogenous genetic material to host cells encoding for a viral or bacterial antigen in order to induce a robust immune response by closely mimicking live infection. The delivery of genetic material requires a carrier …

Impact-Resistant Behavior Of Reinforced Concrete Bridge Columns, Chen Fang

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The damage caused by a vehicle collision on a pier column can be catastrophic for the functionality of a bridge, even a total collapse of the bridge. ❖ A vehicle collision and a subsequent vehicle blast cause more damages on the bridge. ❖ Limited researches have been conducted to investigate the behavior of the bridge subjected to the combined effect of vehicle collision and blast. ❖ It is necessary to analyze the responses of the bridge under the vehicle collision and blast and provide some design suggestions to strengthen the bridge.

Conclusions ❖ The finite element models including column, pile …

Optimizing Steel Railway Truss Bridge Health Monitoring, Ahmed Rageh, Daniel Linzell

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Problems - Steel Railway Trusses • Aging • Large system – bridge AND railway • Labor intensive condition eval • Reported conditions: Stringer-to-floor beam connections [Haghani 2012] Stringer flange clip angle cracks [Haghani 2012] Unequal eyebars stress distribution [DelGrego 2008] Displaced eyebar pins [DelGrego 2008

Problems – Condition Evaluation • Visual inspection: Prescribed frequency Costly Subjected to human interpretation • Sensors: Focused on a single bridge Extensive array Costly

Influence Of Skew And Nonlinear Deck On Elastic Versus Inelastic Distribution Behavior And Ultimate Capacity Of Steel Girder Bridges, Fayaz Sofi, Joshua Steelman

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Research Objectives

• Assessment of alternative load distribution methodologies for potential discrepancies that arise when evaluating distribution behavior of skewed steel girder bridges.

• Investigate the influence of skew and material nonlinearities (concrete cracking and steel yielding) on

• Load distribution behavior (elastic versus inelastic).

• System capacities (yielding and ultimate).

Summary and Conclusions • Influence of skew was examined on load distribution behavior, and nonlinear system-based capacities (yielding and ultimate) of composite steel girder bridges in presence of full material nonlinearities. In addition, assessment of two general definitions (beam-line and response fraction approaches) for quantifying load distribution behavior was …

Hyperelastic Structural Fuses For Steel Buildings, Francys López

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Why to upgrade traditional systems?

The FEMA P-58-1 listed some of the limitations in present-generation procedures:

Questions regarding the accuracy and reliability of available analytical procedures in predicting actual building response.

“High” level of conservatism underlying the acceptance criteria.

Inability to reliably and economically apply performance-based procedures to the design of new buildings; and Lack of alternative ways of communicating performance to stakeholders that is more meaningful and useful for decision making purposes.

Performance based design (PBD) emerges as the methodology aiming to bridge this gap, raising the design level performance from life safety (traditional systems) to keep structures fully …

Oxidation Of Ti2Alc In High Temperature Steam Environment, Ziyad M. Smoqi

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

High temperature oxidation of fuel cladding materials, during the loss of coolant accident (LOCA), is of utmost importance for next-generation nuclear energy systems. Ti₂AlC is a promising candidate material for nuclear applications due to its outstanding properties such as thermal stability at high temperatures, oxidation resistance in air, thermal shock resistance, low neutron absorption cross-section, and the resistance to irradiation-induced amorphization. In this research, high temperature steam oxidation experiments were conducted to evaluate the oxidation resistance of Ti₂AlC in LOCA conditions. After oxidation in 100% steam at 600 and 800˚C, the oxidation kinetics followed a parabolic …

Influence Of Internal Variability On Population Exposure To Hydroclimatic Changes, Justin S. Mankin, Daniel Viviroli, Mesfin Mekonnen, Arjen Y. Hoekstra, Radley M. Horton, Jason E. Smerdon, Noah S. Diffenbaugh

Daugherty Water for Food Global Institute: Faculty Publications

Future freshwater supply, human water demand, and people’s exposure to water stress are subject to multiple sources of uncertainty, including unknown future pathways of fossil fuel and water consumption, and ‘irreducible’ uncertainty arising from internal climate system variability. Such internal variability can conceal forced hydroclimatic changes on multi-decadal timescales and near-continental spatial-scales. Using three projections of population growth, a large ensemble from a single Earth system model, and assuming stationary per capita water consumption, we quantify the likelihoods of future population exposure to increased hydroclimatic deficits, which we define as the average duration and magnitude by which evapotranspiration exceeds precipitation …

Ip Flow Mobility In The Industry: From An Economic Perspective, Jun Huang, Fang Fang, Cong-Cong Xing, Yi Qian

Department of Electrical and Computer Engineering: Faculty Publications

The popularity of social media together with the advancement of mobile Internet applications enabling the uploading of data plays a dominant role in the entire Internet traffic. IP flow mobility (IFOM) is proposed as an effective means to enhance the system capacity by offloading data from the cellular network to WiFi or Femtocells or other complementary networks. Although IFOM has been extensively investigated during the past few years, most of these studies, however, are concerned with IFOM technical issues only; little work regarding the IFOM application has been done from the service providers’ perspective. Unlike previous research, in this paper, …

Making Light-Weight Mg-Metal Laminated Nanocomposites, Soodabeh Azadehranjbar, Xinyan Xie, Jeffrey E. Shield, Jian Wang

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Magnesium is the lightest of all the engineering metals. Replacing steel structural materials with Mg-based materials in automotive applications would boost fuel. However, conventional Mg alloys typically suffer from low strength and poor deformability due to very few slip systems and easy twinning. Alloying Mg with other materials and microstructural engineering are promising approaches to increase ductility and strength of Mg. According to Wang et al., interfaces with low energy and high coherency may effectively constrict the nucleation of twins in Mg. In this work, Mg-metal multilayered nanocomposites will be produced by melt spinning procedure and the layers’ mechanical properties …

Negahban Group Report: Saw-Tooth Shear Response Of Aged Poly(Methyl Methacrylate) (Pmma), Mehrdad Negahban

Department of Mechanical and Materials Engineering: Faculty Publications

Results for isothermal saw-tooth shear loading experiments conducted on annealed and oven-cooled poly(methyl methacrylate) (PMMA) at temperatures between 50^oC and 140^oC. The experiments were conducted 1996.

Protocol To Evaluate And Load Rate Existing Bridges, Maria Szerszen, Ali Alhajami

Nebraska Department of Transportation: Research Reports

Load tests can be used to verify component and system performance under a known live load and provide an alternative evaluation methodology to analytically computed the load rating of a bridge. Procedures for nondestructive load testing, which involves field observations and measurements of in- service bridges and field testing often can revel additional capacity since analytical bridge rating tend to be fairly conservative. The goal of presented research was to develop a data-driven rating process to assess and rate bridges. This data-driven rating system reduces the subjective judgment of the bridge inspectors through the use of computer models and field …

Indicators Of Assessing Vehicle Safety Status Under Platoon Conditions At Freeway, Jianan Zhou

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Issue on level freeway segment (Interstate 80) in Nebraska: • High truck percentage (higher than 25%) • Different speed profile - The speed of trucks are set to 67 mph, on average. - The speed of passenger cars are 75 mph, on average. • Result platoons - Approximately 85% of vehicles are observed in platoon. - the degree of freedom to maneuver for drivers are constrained by other in-platoon vehicles. - Vehicles in platoons may face unsafe situation. Goal: Develop indicators to assess the safety status of vehicles under platoon conditions at level freeway segment.

The data were collected at …