Engineering Commons^™

Associative Cad References In The Neutral Parametric Canonical Form, Daniel Robert Staves

Theses and Dissertations

Due to the multiplicity of computer-aided engineering applications present in industry today, interoperability between programs has become increasingly important. A survey conducted among top engineering companies found that 82% of respondents reported using 3 or more CAD formats during the design process. A 1999 study by the National Institute for Standards and Technology (NIST) estimated that inadequate interoperability between the OEM and its suppliers cost the US automotive industry over $1 billion per year, with the majority spent fixing data after translations. The Neutral Parametric Canonical Form (NPCF) prototype standard developed by the NSF Center for e-Design, BYU Site offers …

Increasing The Capacities Of Cable Cars For Use In Public Transport, Sergej Težak, Drago Sever, Marjan Lep

Journal of Public Transportation

This paper examines the advantages and disadvantages of cable cars in public transport within urban areas. The advantages of cable car transport compared to other modes of transport are its quiet operation with an environmentally-acceptable electric drive and the possibility of transporting passengers above the ground, which can provide additional transport dimensions within urban centers. However, cable cars have some disadvantages, especially their smaller capacities in relation to other modes of transport within the urban environment. Today's built cable cars have capacities up to 2,000 persons/h for aerial tramways (or jig-back ropeways) and up to 4,000 persons/h for gondolas.

Solutions …

Willingness To Use A Public Bicycle System: An Example In Nanjing City, Peiyu Feng, Wenquan Li

Journal of Public Transportation

The purpose of this paper is to examine the influence factors on willingness to use a public bicycle system and to analyze the impact of each. Ordered Logit and Probit models were used to analyze the change in user willingness after improvements were made. Data were collected from a random survey conducted in September and October 2014 in Nanjing, China. The findings of this research indicate seven factors that most influence willingness to use a public bicycle system, including socioeconomic factors and journey restrictions. Socioeconomic factors (gender, employment, and car ownership) have more impact on user willingness than journey restrictions. …

The Effects Of Access And Accessibility On Public Transport Users’ Attitudes, Subeh Chowdhury, Kasey Zhai, Asif Khan

Journal of Public Transportation

This study investigates existing users’ attitudes towards public transport from two perspectives. First, the effects of accessibility to various destinations and ease of access to terminals on public transport users’ attitudes are determined. Second, the contribution of social norm, as an information source, in the formation of users’ attitudes is assessed. A user-preference survey was undertaken in Auckland, New Zealand, at two terminals. Data were analyzed using ordinal and logistic regression models. Findings showed that residential density and quality of the built environment, particularly safety, have an effect on the number of pedestrians who access a terminal. Accessibility to various …

Numerical Simulation Of Shock Response And Dynamic Fracture Of A Concrete Dam Subjected To Impact Load, Lu Lu, Xin Li, Jing Zhou, Genda Chen, Dong Yun

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The shock response and dynamic fracture of concrete gravity dams under impact load are the key problems to evaluate the antiknock safety of the dam. This study aims at understanding the effects of impact shock on the elastic response and dynamic fracture of concrete gravity dams. Firstly, this paper uses acceleration records of a concrete gravity dam under impact to establish the correct way to determine the concrete gravity dam of the fundamental frequency and present cut sheets multi-degree-of-freedom dynamic modeling. Under strong impact loading, the constitutive relation of concrete gravity dam and the highest frequency of the impact are …

Flight Physician - March, 2016, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

A twenty-five page newsletter of the Civil Aviation Medical Association. The newsletter provided news about civil aviation medicine and information related to the organization.

Scale Effect Of Premixed Methane-Air Combustion In Confined Space Using Les Model, Liang Wang, Sisi Que, Jerry C. Tien, Nassib Aouad

Mining Engineering Faculty Research & Creative Works

Gas explosion is the most hazardous incident occurring in underground airways. Computational Fluid Dynamics (CFD) techniques are sophisticated in simulating explosions in confined spaces; specifically, when testing large-scale gaseous explosions, such as methane explosions in underground mines. The dimensions of a confined space where explosions could occur vary significantly. Thus, the scale effect on explosion parameters is worth investigating. In this paper, the impact of scaling on explosion overpressures is investigated by employing two scaling factors: The Gas-fill Length Scaling Factor (FLSF) and the Hydraulic Diameter Scaling Factor (HDSF). The combinations of eight FLSFs and five HDSFs will cover a …

Identifying The Presence Of Amd-Derived Soil Co₂ In Field Investigations Using Isotope Ratios, Kwame Awuah-Offei, Moagabo Mathiba, Fred J. Baldassare

Mining Engineering Faculty Research & Creative Works

Recent incidents of hazardous accumulations of CO₂ in homes on or adjacent to reclaimed mine land have been shown to be linked to neutralization reactions between acidic mine drainage and carbonate material. An efficient and economic method is necessary to identify the presence of acid mine drainage- (AMD-) derived CO₂ on reclaimed mine land, prior to construction. One approach to identify the presence of AMD-derived CO₂ is to characterize stable carbon isotope ratios of soil CO₂. To do so, a viable method is necessary to acquire soil gas samples for isotope ratio analysis. This paper …

Pharmaceuticals, Endocrine Disruptors, Personal Care Products, Nanomaterials And Perfluorinated Pollutants: A Review, Jimoh O. Tijani, Ojo O. Fatoba, Omotola O. Babajide, Leslie F. Petrik

Mining Engineering Faculty Research & Creative Works

The presence of emerging micropollutants such as pharmaceuticals, endocrine disruptors, personal care products, nanomaterials and perfluorinated substances in the environment remains a great threat to the health and safety of humans and aquatic species. These micropollutants enter the environment via anthropogenic activities and have been detected in surface water, groundwater and even drinking water at nanogram per liter to microgram per liter concentration. To date, limited information exists on the fate, behaviors, and pathways of these micropollutants in the environment. The potential ecotoxicological effects on the receptors due to exposure to individual or mixture of these chemicals still remain unknown. …

Shape Dependence Of Transmission, Reflection, And Absorption Eigenvalue Densities In Disordered Waveguides With Dissipation, Alexey Yamilov, Sasha Petrenko, Raktim Sarma, Hui Cao

Physics Faculty Research & Creative Works

The universal bimodal distribution of transmission eigenvalues in lossless diffusive systems underpins such celebrated phenomena as universal conductance fluctuations, quantum shot noise in condensed matter physics, and enhanced transmission in optics and acoustics. Here, we show that in the presence of absorption, the density of the transmission eigenvalues depends on the confinement geometry of the scattering media. Furthermore, in an asymmetric waveguide, the densities of the reflection and absorption eigenvalues also depend on the side from which the waves are incident. With increasing absorption, the density of absorption eigenvalues transforms from a single-peak to a double-peak function. Our findings open …

Influence Of Strong Preformed Particle Gels On Low Permeable Formations In Mature Reservoirs, Mahmoud O. Elsharafi, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In mature reservoirs, the success of preformed particle gel (PPG) treatment rests primarily on the ability of the PPG to reduce and/or plug the high permeable formations but not damage the low permeable formations. Static test models (filtration test model and pressure test model) were used to determine the effect of PPG on low permeable formations. This work used a strong preformed particle gel, Daqing (DQ) gel made by a Chinese company. The particle gel sizes were ranged from 30 to 120 mesh for this work. PPGs are sized in a millimeter or micrometer, which can absorb over a hundred …

Enhancing A Flight Dispatcher Display For Safer Flight Operations, Jeongjoon Boo

Open Access Theses

This study assesses capability of flight dispatchers to adopt enhancements on their display that enables detection of flights in abnormal activities and investigation of the causes. Three approaches were used. First, the expected function for enhancements was designed by collecting information from different places about what technologies are available for consideration. Second, hierarchical task analysis was conducted based on data collected by interviewing a former flight dispatcher in order to assess operational capability to handle the enhancement. Third, based on the results of first two approaches, a display prototype that includes the enhancement was developed and evaluated for usability and …

Modernizing The Current Afghan Engineering Education System: Challenges And Opportunities, Khalilullah Mayar

Open Access Theses

Having an effective engineering education system in place can play a crucial role in the development and reconstruction process of a war-ravaged country, such as Afghanistan, where tens of billions of dollars of international aid has been spent in the past 14 years for that process, including higher education. Unfortunately, at this point, the Afghan engineering education system is not yet financially self-sufficient nor can it address the education requirements of today’s job market. This thesis aimed to identify the major challenges still faced by Afghanistan and to provide a comprehensive list of recommendations and priorities that can make the …

Learning The Language Of Academic Engineering: Sociocognitive Writing In Graduate Students, Catherine G. P. Berdanier

Open Access Dissertations

Although engineering graduate programs rarely require academic writing courses, the indicators of merit in academic engineering, such as journal publications, successful grants, and doctoral milestones (e.g. theses, dissertations) are based in effective written argumentation and disciplinary discourse. Further, graduate student attrition averages 57% across all disciplines, with some studies classifying up to 50% of these students as “ABD” (All But Dissertation.) In engineering disciplines specifically, graduate attrition rates across the U.S. average 36% (both Master’s and PhD students), according to the Council of Graduate Schools. The lack of socialization is generally noted as a main reason for graduate attrition, one …

Hydrologic And Water Quality Impacts From Perennial Crop Production On Marginal Lands, Qingyu Feng

Open Access Dissertations

Marginal lands are proposed as a viable option for producing biofeedstocks as these lands are not heavily engaged in agricultural production or may not be suitable for intensive row-crop food/feed production. However, meeting biofeedstock production goals will require large amount of marginal lands and the unintended consequences of producing biofeedstocks on marginal lands are not fully clear. The overall goal of this study was to evaluate the productivity of biofeedstocks on marginal lands and the potential impacts on hydrologic and water quality processes from the land use conversion.

This study was conducted in the Upper Mississippi River Basin (UMRB). First, …

Analytical Investigation Of Fretting Wear With Special Emphasis On Stress Based Models, Arnab Jyoti Ghosh

Open Access Dissertations

Fretting refers to the minute oscillatory motion between two surfaces in contact under an applied normal load. It can cause either surface or subsurface initiated failure resulting in either fatigue or wear or both. Two distinct regimes – partial slip and gross slip are typically observed in fretting contacts. Due to the nature of contact, various factors such as wear debris, oxidation, surface roughness, humidity etc. effect failures caused due to fretting. A number of different techniques have been developed to quantify fretting damage and several numerical models are proposed to predict damage due to fretting. Fretting wear also depends …

Bond–Slip Behavior Of Fiber-Reinforced Polymer/Concrete Interface In Single Shear Pull-Out And Beam Tests, Tayyebeh Mohammadi, Baolin Wan, Kent A. Harries

Civil and Environmental Engineering Faculty Research and Publications

It has been assumed that the fiber-reinforced polymer/concrete interface is subjected to in-plane shear condition when intermediate crack debonding failure occurs. Therefore, the single shear pull-out test results are often used to predict the intermediate crack debonding failure in beams. In this study, the behavior of fiber-reinforced polymer-strengthened concrete beams and single shear pull-out specimens were studied experimentally and numerically. The bond–slip behavior of the fiber-reinforced polymer/concrete interface was obtained by single shear pull-out and beam tests. In all beam specimens, a concrete wedge located at the edge of the notch detached with the fiber-reinforced polymer debonding failure. This phenomenon …

Faculty Intellectual Property In Capstone Design Projects, Jay R. Goldberg

Biomedical Engineering Faculty Research and Publications

Reports on the Capstone Design challenge, focusing on design challenges for the participants. By focusing on the design process and allowing students to gain hands-on experience in design, they help prepare students for careers in engineering. In many capstone design courses, students design a product or device to solve a problem and build and test a prototype to verify and validate the design. Student teams are often advised by some combination of industry sponsors, clinical advisors, and/or faculty advisors. Faculty advisors serve as technical advisors to the teams and provide guidance to keep them on track. They are not members …

Solvent-Free Manufacturing Of Electrodes For Lithium-Ion Batteries, B. Ludwig, Z. Zheng, W. Shou, Y. Wang, Heng Pan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Semiconductor Film Grown On A Circular Substrate: Predictive Modeling Of Lattice-Misfit Stresses, Ephraim Suhir, Johann Nicolics, G. Khatibi, M. Lederer

Mechanical and Materials Engineering Faculty Publications and Presentations

effective and physically meaningful analytical predictive model is developed for the evaluation the lattice-misfit stresses (LMS) in a semiconductor film grown on a circular substrate (wafer). The two-dimensional (plane-stress) theory-of-elasticity approximation (TEA) is employed in the analysis. The addressed stresses include the interfacial shearing stress, responsible for the occurrence and growth of dislocations, as well as for possible delaminations and the cohesive strength of a buffering material, if any. Normal radial and circumferential (tangential) stresses acting in the film cross-sections and responsible for its short- and long-term strength (fracture toughness) are also addressed. The analysis is geared to the GaN …

Predicting Construction Labor Productivity With Bayesian Belief Networks, Ayoub Hazrati

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Construction labor productivity plays an important role in labor intensive projects. Therefore, increasing construction labor productivity is a vital task to decrease a project’s cost (time). The primary goal of this research is to investigate the feasibility of developing a comprehensive causal model that can predict construction labor productivity for various project’s situations, such as existence of “Adverse Weather,” “Changes,” “Working Overtime,” etc., while considering uncertainty. It is found that Bayesian Belief Networks (BBNs) is the best approach that can model causal relationships among different factors while considering uncertainty, simultaneously.

Developing a BBNs model requires to extract its structure and, …

Evaluation Of Lightweight Pieces In Aggregates, Mark Lindemann, Doug Macke, Jim Wilken, John Ebito, Mark Hassler, Lieska Halsey, Bob Seger

Nebraska Department of Transportation: Research Reports

Nebraska Department of Roads (NDOR) Material and Research (M&R) Division started an evaluation to determined injurious deleterious lightweight pieces of aggregate from a dry pit location, as a result of field observations from a project stock pile. This brief summary presents the field observation and laboratory testing evaluations to determine the percent of lightweight pieces in aggregate.

Evaluation Of Lightweight Pieces In Aggregates, Mark Lindemann, Doug Macke, Jim Wilken, John Ebito, Mark Hassler, Lieska Halsey, Bob Seger

Nebraska Department of Transportation: Research Reports

No abstract provided.

Active Traffic Management Case Study: Phase 1, Anuj Sharma, Shuo Wang, Aemal Khattak

Nebraska Department of Transportation: Research Reports

This study developed a systematic approach for using data from multiple sources to provide active traffic management solutions. The feasibility of two active traffic management solutions is analyzed in this report: ramp-metering and real-time crash risk estimation and prediction. Using a combined dataset containing traffic, weather, and crash data, this study assessed crash likelihood on urban freeways and evaluated the economic feasibility of providing a ramp metering solution. A case study of freeway segments in Omaha, Nebraska, was conducted. The impact of rain, snow, congestion, and other factors on crash risk was analyzed using a binary probit model, and one …

Design And Validation Of A Fall Detection Application For Ios, Connor Lewis Mosley

Master's Theses

Despite significant preventative efforts, falls continue to be a major source of morbidity and mortality among the elderly. Additionally, the fear of falling can be a major obstacle to independent living for otherwise self-sufficient individuals. This fear is significantly heightened in individuals who have sustained a fall and often results in self-imposed restrictions on mobility and exercise, causing weakening in these individuals and further exacerbating the danger. Much time has been spent developing alert systems in an attempt to mitigate these problems. Unfortunately these systems typically involve dedicated monitoring centers and therefore often come with substantial upfront and recurring costs. …

Oceanographic Instrument Simulator, Amy Chen

Master's Theses

The Monterey Bay Aquarium Research Institute (MBARI) established the Free Ocean Carbon Enrichment (FOCE) experiment to study the long-term effects of decreased ocean pH levels by developing in-situ platforms [1]. Deep FOCE (dpFOCE) was the first platform, which was deployed in 950 meters of water in Monterey Bay. After the conclusion of dpFOCE, MBARI developed an open source shallow water FOCE (swFOCE) platform located at around 250 meter of water to facilitate worldwide shallow water experiments on FOCE [1][2]. A shallow water platform can be more ubiquitous than a deep-water platform as shallow water instruments are less expensive (as it …

Lunar Icecube Space Mission, Robert J. Twiggs, Eric Jerde

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professors Bob Twiggs and Eric Jerde titled "Lunar IceCube Space Mission" from March 1, 2016.

Enhancing Students Learning And Assessment Through Positive Reinforcement, Philip Appiah-Kubi

Engineering Management and Systems Faculty Publications

Students’ understanding of class material, and knowledge retention are assessed through homework, exams, and a host of other methods. None of these forms of assessment is intrinsically paramount to the others; however, the benefits depend on how well they are used. A good assessment depends on the purpose and learning objectives, and one way of maximizing the benefits of assessment is to involve students in the assessment methodology. This paper evaluates the benefits of having students prepare some of the questions for their final exams. Generally, students put in more effort when they understand that they are in charge. Each …

A Techno-Economic Analysis Of Wind Generation In Conjunction With Compressed Air Energy In The Integrated Single Electricity Market., Brendan Cleary

Doctoral

The Integrated Single Electricity Market (I-SEM) is the proposed wholesale electricity market for Ireland and it is intended to replace the current Single Electricity Market (SEM) by 2018. Subsequently, substantial modifications will be required to the SEM and this has led to significant uncertainty for stakeholders. The SEM currently features no forecast risk for renewables such as wind and there is no concept of balance responsibility. Under the I-SEM, wind generation will be exposed to forecast risk and the requirement to be balance responsible. The use of Compressed Air Energy Storage (CAES) could represent a better system configuration which would …

Instrumented Lumbar Corpectomy And Spinal Reconstruction Comparing Rhbmp-2/Compression-Resistant Matrix, Rhbmp-2/Absorbable Collagen Sponge/Ceramic Granules Mixture, And Autograft In Two Different Devices: A Study In Sheep, Jeffrey M. Toth, David G. Schwartz, Jean-Piere Mobasser, Joseph Williams

Biomedical Engineering Faculty Research and Publications

Study Design. Fusion success with rhBMP-2 and autograft in titanium or PEEK corpectomy devices was evaluated in a sheep lumbar corpectomy model. The 6 treatment groups included titanium mesh or PEEK corpectomy devices filled with rhBMP-2 on a compression-resistant matrix (CRM) carrier; rhBMP-2 in a morselized absorbable collagen sponge (ACS) carrier combined with resorbable ceramic granules; and autograft.

Objective. The aim of this study was to determine fusion rates associated with 2 different preparations of rhBMP-2 as well as autograft in an instrumented ovine lumbar corpectomy model 6 months postoperatively.

Summary of Background Data. Vertebral reconstruction with corpectomy devices requires …