Engineering Commons^™

Stability Analysis Of A More General Class Of Systems With Delay-Dependent Coefficients, Chi Jin, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper presents a systematic method to analyse the stability of systems with single delay in which the coefficient polynomials of the characteristic equation depend on the delay. Such systems often arise in, for example, life science and engineering systems. A method to analyze such systems was presented by Beretta and Kuang in a 2002 paper, but with some very restrictive assumptions. This work extends their results to the general case with the exception of some degenerate cases. It is found that a much richer behavior is possible when the restrictive assumptions are removed. The interval of interest for the ...

Slip Of Shuffle Screw Dislocations Through Tilt Grain Boundaries In Silicon, Hao Chen, Valery Levitas, Liming Xiong

Aerospace Engineering Publications

In this paper, molecular dynamics (MD) simulations of the interaction between tilt grain boundaries (GBs) and a shuffle screw dislocation in silicon are performed. Results show that dislocations transmit into the neighboring grain for all GBs in silicon. For Σ3, Σ9 and Σ19 GBs, when a dislocation interacts with a heptagon site, it transmits the GB directly. In contrast, when interacting with a pentagon site, it first cross slips to a plane on the heptagon site and then transmits the GB. The energy barrier is also quantified using the climbing image nudged elastic band (CINEB) method. Results show that Σ3 ...

Critical Analysis Of Case Law: Are Partnering Charters Binding?, Milagros Pinto Nunez, Douglas D. Gransberg

Civil, Construction and Environmental Engineering Publications

Construction project partnering in the United States has been used successfully for nearly 30 years in reducing disputes. Most partnered projects are characterized by the joint development of a nonbinding partnering charter between the owner and the contractor, which encapsulates the project’s goals and lays out the desired process for resolving issues at the lowest level. This paper explores the outcomes when partnered projects fail and the parties involved must turn to the courts to settle their disputes. The paper evaluates the case law for 16 partnered projects through content analysis and cross-case comparison. The paper explores the question ...

Rc Baja: Drivetrain, Nick Paulay

All Undergraduate Projects

The American Society of Mechanical Engineers (ASME) annually hosts an RC Baja challenge, testing a RC car in three events: slalom, acceleration and Baja. Although ASME will not be holding an event this year, CWU will be holding an event with three RC Baja car teams from CWU as well as other teams from local colleges. The RC car that is tested in these events is designed and manufactured typically in teams of two. The RC car that each team submits must be able to complete these events to score points. One part of great importance for the RC car ...

Validating The Opa Cascading Blackout Model On A 19402 Bus Transmission Network With Both Mesh And Tree Structures, Benjamin A. Carreras, Jose M. Reynolds-Barredo, Ian Dobson, David E. Newman

Electrical and Computer Engineering Conference Papers, Posters and Presentations

The OPA model calculates the long-term risk of cascading blackouts by simulating cascading outages and the slow process of network upgrade in response to blackouts. We validate OPA on a detailed 19402 bus network model of the Western Electricity Coordinating Council (WECC) interconnection with publicly available data. To do this, we examine scalings on a series of WECC interconnection models with increasing detail. The most detailed, 19402 bus network has more tree structures at the edges of the main mesh structure, and we extend the OPA model to account for this. The higher-risk cascading outages are the large cascades that ...

Thin-Film Sensor For Fatigue Crack Sensing And Monitoring In Steel Bridges Under Varying Crack Propagation Rates And Random Traffic Loads, Xiangxiong Kong, Jian Li, Caroline Bennett, William Collins, Simon Laflamme, Hongki Jo

Civil, Construction and Environmental Engineering Publications

Fatigue cracks are critical structural concerns for steel highway bridges, and fatigue initiation and propagation activity continues undetected between physical bridge inspections. Monitoring fatigue crack activity between physical inspections can provide far greater reliability in structural performance and can be used to prevent excessive damage and repair costs. In this paper, a thin-film strain sensor, called a soft elastomeric capacitor (SEC) sensor, is evaluated for sensing and monitoring fatigue cracks in steel bridges. The SEC is a flexible and mechanically robust strain sensor, capable of monitoring strain over large structural surfaces. By deploying multiple SECs in the form of dense ...

Grain Boundary Induced Deformation Mechanisms In Nanocrystalline Al By Molecular Dynamics Simulation: From Interatomic Potential Perspective, Liang Zhang, Yasushi Shibuta, Xiaoxu Huang, Cheng Lu, Mao Liu

Faculty of Engineering and Information Sciences - Papers: Part B

Nanocrystalline metals exhibit many excellent mechanical properties and their underlying deformation mechanisms have been studying widespread. The well-designed atomistic simulations can predict the mechanical behavior of materials ahead of experiments and provide sufficient information on the atomic scale. The choice of appropriate interatomic potential is one of the main concerns of any atomistic simulation that needs to be seriously considered in order to obtain reliable results. In this study, we investigated the mechanical response and the deformation mechanisms of nanocrystalline Al under uniaxial loading by molecular dynamics (MD) simulations with different embedded atom method (EAM) interatomic potentials. The selection of ...

A New Method For Direct Tensile Testing Of Concrete, Faez Alhussainy, Hayder Alaa Hasan, M Neaz Sheikh, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part B

Different testing methods were used in previous studies to measure the direct tensile strength of concrete. However, these methods experienced several major deficiencies such as stress concentration at the end of the specimens because of inadequate gripping and loading eccentricity and nonuniform fracture plane because of difficulties in aligning and centering the specimens during testing. This study presents the details of a new method of testing concrete under uniaxial tension. The method was developed to overcome the difficulties associated with testing methods adopted in the previous research studies. A full description of the wooden molds used in casting the specimens ...

Call For Abstracts - Resrb 2019, July 8-9, Wrocław, Poland, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Csar 62 Spin Curve, Mohsen Azadi, Georgia Griggs, Glen De Villafranca, Gerald Lopez

Protocols and Reports

No abstract provided.

Wyoming Wheels, David Tobin

Honors Theses AY 17/18

Manual wheelchair users traditionally suffer from an increased risk of chronic shoulder injury and the inability to travel quickly or uphill independently. Beginning as a senior design project in fall of 2016, Wyoming Wheels is a geared, lever-action, manual wheelchair system designed to mitigate these challenges. For the 2017-2018 school year, the goal of the project was to create a functional prototype by optimizing the previous year’s project. Specifically, the weight and noise output needed to be decreased, and the shifting, braking, and overall ergonomics of the chair needed to be improved. The total weight of the chair was ...

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Creating Holistic Engineers To Solve The Grand Challenges Of The Future, Una Beagon

Articles

Una Beagon writes that continued growth in construction depends on third level Institutions securing a talent pipeline of Civil & Structural Engineers with suitable skill sets to bring about, maintain and operate large multidisciplinary projects.

A Computational Analysis Of The Gradient Concentration Profile Of Deet And The Mosquito Behavioral Response, Brandon Carver

Master's Theses

DEET is a common active ingredient in most spatial repellents. DEET is also a volatile organic compound. DEET prevents mosquitoes from detecting and coming into contact with an human individual. Gas sensing technologies such as metal oxide semiconductor sensors can detect VOCs. The World Health Organization provides the majority of efficacy testing methods. This research adapts methods from the WHO and use of MOS sensors to further understand how and why DEET affects mosquitos. A custom developed system is used to measure DEET dissipation and observe mosquito behavioral response to the DEET. DEET dissipations and mosquito behavior is measured within ...

Epics Gaqt: Nandi Clean Kitchen Study, Yichen Fan

Engagement & Service-Learning Summit: Connecting Through Listening & Scholarship

No abstract provided.

Analysis And Simulation Of Convolution Reverb Using City Tech’S New Auditorium, Tian Leng

Publications and Research

In digital signal processing, convolution reverb can simulate the reverberation of a real acoustic space. The acoustics of different seating areas in an auditorium can vary from each other. To determine the reverberant characteristics of City Tech new building’s auditorium, impulse response (IR) signals are recorded in five key locations of the auditorium.

Directly recorded balloon burst is chosen as the source of impulse source. An omnidirectional and a cardioid microphone with flat frequency response curves are used to record IR signals to 24-bit monophonic wav files. Each IR signal, along with a vocal, is convoluted in MATLAB through ...

Purdue Epics And Habitat For Humanity Partnership - Service-Learning For Over 20 Years, Trevor A. Drouillard, Sue Hunter

Engagement & Service-Learning Summit: Connecting Through Listening & Scholarship

For over twenty years, the Lafayette affiliate of Habitat for Humanity has partnered with the Purdue University EPICS program to connect students to real-world problems where they can learn engineering through experience. Past projects have focused on improving material storage methods, enhancing volunteer safety, developing energy-efficient building designs, and optimizing operational efficiency at Habitat for Humanity locations. The partnership is mutually beneficial for Habitat for Humanity – which benefits from the products students deliver – and for students – who learn how to apply engineering to real-world design. This poster represents a summary of what the EPICS – Habitat for Humanity partnership has produced ...

Community-Scale Water Treatment Systems In The Dominican Republic, Jonathan Racey, Annabelle Papai, Elise Fischer, Becca Johnson

Engagement & Service-Learning Summit: Connecting Through Listening & Scholarship

Engagement and Service-Learning Summit: Reciprocal and Sustainable Partnerships

Amplification Of Earthquake Ground Motions In Washington, Dc, And Implications For Hazard Assessments In Central And Eastern North America, Thomas L. Pratt, J. Wright Horton Jr., Jessica Munoz, Susan E. Hough, Martin C. Chapman, C. Guney Olgun

C. Guney Olgun

The extent of damage in Washington, DC, from the 2011 M_W 5.8 Mineral, VA, earthquake was surprising for an epicenter 130 km away; U.S. Geological Survey “Did-You-Feel-It” reports suggest that Atlantic Coastal Plain and other unconsolidated sediments amplified ground motions in the city. We measure this amplification relative to bedrock sites using earthquake signals recorded on a temporary seismometer array. The spectral ratios show strong amplification in the 0.7 to 4 Hz frequency range for sites on sediments. This range overlaps with resonant frequencies of buildings in the city as inferred from their heights, suggesting amplification ...

Arts Integration Into Elementary Science: Force And Motion And Natural Disasters, Eric C. Ooms, Tabitha M. Wu, Ashley R. Kokemuller, Sarah E. Montgomery, Audrey C. Rule

Journal of STEM Arts, Crafts, and Constructions

This study explored the effect of arts integration into science during an instructional unit on force and motion and one addressing natural weather disasters. Seventy-eight elementary students in four classrooms (grade 5, grade 4, and two at grade 3) participated in the study. This study assessed content retention, student-made products (rollercoasters and hurricane shelters), and student attitudes. All students in each classroom experienced the two units of instruction, one unit in the experimental condition of arts integration and one unit in the control condition without arts integration. Both conditions involved students in constructing models of given materials. Each unit consisted ...