Engineering Commons^™

Soils Magic: Bringing Civil Engineering To The K–12 Classroom, David J. Elton, James Hanson, David M. Shannon

Civil and Environmental Engineering

An investigation was conducted to assess the effectiveness of a series of kindergarten through 12th grade (K–12) educational outreach activities related to civil engineering. In particular, a program called Soils Magic that contains a series of simple geotechnical engineering experiments was delivered in various formats to K–12 students. This paper provides an overview of the Soils Magic program and provides further details of selected experiments from the program. This paper highlights the experiences of various civil engineering professors bringing the program to school children to promote the excitement and accessibility of the engineering profession. Suggestions are provided for conducting successful …

Global Challenges As Inspiration: A Classroom Strategy To Foster Social Responsibility, Linda Vanasupa, Lynn Slivovsky, Katherine C. Chen

Materials Engineering

Social responsibility is at the heart of the Engineer’s Creed embodied in the pledge that we will “dedicate [our] professional knowledge and skill to the advancement and betterment of human welfare...[placing] public welfare above all other considerations.” However, half century after the original creed was written, we find ourselves in a world with great technological advances and great global-scale technologically-enabled peril. These issues can be naturally integrated into the engineering curriculum in a way that enhances the development of the technological skill set. We have found that these global challenges create a natural opportunity to foster social responsibility within the …

Nanotechnology, Biology, Ethics And Society: Overcoming The Multidisciplinary Teaching Challenges, Linda Vanasupa, Matthew Ritter, Barbara Schader, Katherine C. Chen, Richard N. Savage, Peter Schwartz, Lynne Slivovsky

Materials Engineering

One of the inherent challenges of teaching any emerging technology like nanotechnology, is the fact that its core competencies flux in the new disciplines' early stages. Nanotechnology presents an additional challenge in that its underpinnings cross multiple traditional disciplinary boundaries. We have designed a course that aims to address some of these challenges through a handful of structural features: team-based learning; a "reverse of the learning pyramid" approach; team-teaching; embedded information literacy techniques; and application-centered content. Our course is organized around four applications that are in their developmental stages: gold nanoshells for cancer treatment; molecular manufacturing; tissue engineering of a …

Test Methods And Results For Sensors In A Pre-Crash Detection System, Charles Birdsong, Peter Schuster, John Carlin, Daniel Kawano, William Thompson

Mechanical Engineering

Automobile safety can be improved by anticipating a crash before it occurs and thereby providing additional time to deploy safety technologies. This requires an accurate, fast and robust pre-crash sensor that measures telemetry, discriminates between classes of objects over a range of conditions, and has sufficient range and area of coverage surrounding the vehicle. The sensor must be combined with an algorithm that integrates data to identify threat levels. No one sensor provides adequate information to meet these diverse and demanding requirements. However the requirements can be met with an optimal combination of multiple types of sensors. Previous work considered …

Effect Of Low Molecular Weight Heparin On Fracture Healing In A Stabilized Rat Femur Fracture Model, David J. Hak, Rena L. Stewart, Scott J. Hazelwood

Biomedical Engineering

The purpose of this studywas to evaluate the effect of low molecular weight heparin (LMWH) on fracture healing in a standard stabilized rat femur fracture model. A closed, mid-diaphyseal transverse fracture was created in the right femur of Long-Evans rats after insertion of a 0.8-mm K-wire into the medullarycanal. Animals were randomized to receive either LMWH (70 units/kg dalteparin) oraninjection of normal saline daily for 2 weeks. Animals were sacrificed at 2, 3, and 6 weeks. Fracture healing was assessedbyradiographs, histology, and mechanical testing. There were no significant differences between the control and LMWH groups in the percentage of animalswith …

System And Method For An If-Sampling Transceiver, Jack P. Glas, Vladimir I. Prodanov

Electrical Engineering

The present invention is directed toward a radio, and method for receiving radio frequency signals. The radio comprises an input signal at a first intermediate frequency, an intermediate sampling architecture, a quantizer and a baseband converter. The intermediate frequency sampling architecture comprises receiving the input signal, passing the first intermediate frequency signal through a first filter characterized by steep selectivity and narrow bandpass, converting the filtered signal to a second intermediate frequency and passing the second intermediate frequency signal through a second filter having a bandpass characteristic, but without the steep selectivity characterizing the first filter. The radio further comprises …

Post Register Allocation Spill Code Optimization, Christopher Lupo, Kent Wilken

Computer Science and Software Engineering

A highly optimized register allocator should provide an efficient placement of save/restore code for procedures that contain calls. This paper presents a new approach to placing callee-saved save and restore instructions that generalizes Chow's shrink-wrapping technique (Chow 1988). An efficient, profile-guided, hierarchical spill code placement algorithm is used to analyze the structure of a procedure to calculate the minimum dynamic execution count locations to place callee-saved save and restore code. The algorithm is implemented in the Gnu Compiler Collection and has been tested on the SPEC CPU2000 Integer Benchmark suite. Results show that the technique reduces the number of dynamic …

Normalizing The Cpt For Overburden Stress, Robb E.S. Moss, Raymond B. Seed, Richard S. Olsen

Civil and Environmental Engineering

Effective overburden stress can have a significant influence on cone penetration test (CPT) measurements. This influence can lead to an incorrect assessment of soil strength/resistance for such purposes as liquefaction triggering analysis. For an accurate measurement of tip and sleeve resistance, unbiased by overburden stress, it is essential to normalize these index measurements appropriately. Presented herein is a comprehensive study reviewing all aspects of CPT normalization. A result of this study is a variable normalization procedure for the CPT that is based on both empirical results and theoretical analysis. This paper presents these results in the form of an improved …

Atms Implementation System For Identifying Traffic Conditions Leading To Potential Crashes, Mohamed Abdel-Aty, Anurag Pande

Civil and Environmental Engineering

Predicting a crash occurrence is the key to traffic safety. Real-time identification of freeway segments with high crash potential is addressed in this paper. For this study, historical crashes and corresponding traffic-surveillance data from loop detectors were gathered from a 36-mi corridor of Interstate 4 for 4 years. Following an exploratory analysis, two types of logistic-regression models (i.e., simple and multivariate) were developed. It was observed that, although the simple models have the advantage of being tolerant in their data requirements, their classification accuracy was inferior to that of the final multivariate model. Hence, the simple models were used to …

Processing Model For Tungsten Powders And Extention To Nanoscale Size Range, Randall M. German, J. Ma, X. Wang, E. Olevsky

Industrial and Manufacturing Engineering

Nanoscale tungsten powders promise access to very hard, strong and wear resistant materials via the press–sinter route. A small particle size changes the response during sintering, requiring lower temperatures and shorter times to attain dense but small grain size structures. On the other hand, oxide reduction and impurity evaporation favour high sintering temperatures and long hold times. Accordingly, press–sinter processing encounters conflicting constraints when applied to small particles. Presented here is an analysis of press–sinter tungsten particle processing to isolate conditions that balance the temperature and size dependent effects. The calculations are pinned by existing data. Opportunities are identified for …

Neural-Electronic Inhibition Simulated With A Neuron Model Implemented In Spice, Robert B. Szlavik, Abuhanif K. Bhuiyan, Anthony Carver, Frank Jenkins

Biomedical Engineering

There have been numerous studies presented in the literature related to the simulation of the interaction between biological neurons and electronic devices. A complicating factor associated with these simulations is the algebraic complexity involved in implementation. This complication has impeded simulation of more involved neural-electronic circuitry and consequently has limited potential advancements in the integration of biological neurons with synthetic electronics. In this paper, we describe a modification to a previously proposed SPICE based Hodgkin-Huxley neuron model that demonstrates more physiologically relevant electrical behavior. We utilize this SPICE based neuron model in conjunction with an external circuit that allows for …

A 32-Mw 320-Mhz Continuous-Time Complex Delta-Sigma Adc For Multi-Mode Wireless-Lan Receivers, Jesus Arias, Peter Kiss, Vladimir Prodanov, Vito Boccuzzi, Mihai Banu, David Bisbal, Jacinto San Pablo, Luis Quintanilla, Juan Barbolla

Electrical Engineering

We present an experimental continuous-time complex delta-sigma multi-bit modulator, implemented in standard 0.25-μm CMOS technology and meeting all major requirements for application in IEEE 802.11a/b/g wireless LAN receivers. The clock frequency is 320 MHz, producing an oversampling ratio of 16 for 20 MHz channel bandwidths. The modulator supports two operation modes for zero-IF and low-IF receiver architectures respectively, requires a single 2.5-V power supply, and dissipates only 32 mW of power. The measured peak signal-to-noise ratio is 55 dB. Further experimental results using sine-wave and OFDM test signals are also presented

Ultrasonic Method For Aircraft Wake Vortex Detection, Rebecca J. Rodenhiser, William W. Durgin, Hamid Johari

Office of the Provost Scholarship

This paper describes the experimental proof of concept study for an ultrasonic method of wake vortex detection for airport use. This new acoustic method utilizes travel time of acoustic pulses around a closed path to measure the net circulation within the acoustic path. In this application the closed path encloses the vorticity shed from one side of a Piper PA28 aircraft wing. Magnitude and sign of circulation detected is comparable to the expected circulation generated by the Piper PA28 test aircraft. This study demonstrates the validity of the acoustic method in detecting aircraft wake vortices. Further investigations and applications utilizing …

Experimental Evaluation Of A High Fineness Ratio Body With Drag Brakes, Corey J. Florendo, Thomas R. Yechout, Stefan Siegel, Russell M. Cummings, Joseph Kealos

Aerospace Engineering

The Advanced Remote Ground Unattended Sensor uses drag brakes to control its terminal velocity during flight. An experimental evaluation of the geometry was performed at Mach numbers between 0.20 and 0.50 with a 61.5% scale model in the U.S. Air Force Academy Subsonic Wind Tunnel. Configurations tested include baseline drag brakes fully deployed, an array of perforated drag brake designs, as well as various other related drag brake design features. Improvements to the baseline design are discussed and an improved configuration is presented. Limited unsteady computations were performed for selected cases using detached-eddy simulation to understand various experimental results. The …

Experimental Evaluation Of A High Fineness Ratio Body With Drag Brakes, Corey J. Florendo, Thomas R. Yechout, Stefan G. Siegel, Russell M. Cummings, Joseph Kealos

Aerospace Engineering

No abstract provided.

The Influence Of Viscosity And Surface Curvature On The Pressure Distribution Of A Stream Thrust Probe, Renee Pasman, Russell M. Cummings

Aerospace Engineering

Determining the local stream thrust (a vector quantity) from a measured pitot pressure (a scalar quantity) requires either knowledge of the flow direction, or a probe shape that compensates for flow direction. This compensation would ideally make the measured pressure directly proportional to the component of momentum along the probe axis. The flow angle sensitivity required to resolve this component of momentum was determined theoretically previously. A proposed probe nose shape was analyzed using CFD and found to produce flow angle sensitivity close to the required sensitivity. The proposed nose shape was also tested in a wind tunnel at Mach …

Numerical Evaluation Of The Flowfield For A High Fineness Ratio Body With Drag Brakes, Russell M. Cummings, James A. Divine, Thomas R. Yechout, David C. Wetlesen, Joseph J. Kealos

Aerospace Engineering

The Advanced Remote Ground Unattended Sensor (ARGUS) utilizes drag brakes to control its terminal velocity during flight. Computational fluid dynamics predictions were performed at Mach numbers between 0.20 and 0.95 with a full scale model of the ARGUS configuration at conditions to match wind tunnel testing that has been performed at the USAFA Subsonic Wind Tunnel. Configurations consist of brakes fully deployed for a nominal brake fin and a perforated brake fin. Steady-stated computations were performed using the Spalart-Allmaras turbulence model at angles of attack between 0 degrees to 20 degrees at roll angles of 0 degrees and 45 degrees. …

Simulated Performances Of A Heat Pump System For Energy And Water Conservation In Open And Confined Greenhouse Systems, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The purpose of this study was to determine and compare the performances of conventional and heat pump systems for energy and water conservation in open and confined greenhouse systems. Conventional gas furnaces and evaporative cooling, respectively, provided heating and cooling in the conventional system. In the heat pump systems, gas-fired heat pump units provided both heating and cooling. The greenhouse with heat pump units also had an option to be operated as a completely confined system, using one of the heat pump units as a dehumidifier. Average energy consumption in winter was 56.9, 23.5, and 11.3 MJ/day.m² in the conventional, …

Predictions On Preserving Bone Mass In Knee Arthroplasty With Bisphosphonates, Jeffry S. Nyman, Juan J. Rodrigo, Scott J. Hazelwood, Oscar C. Yeh, R. Bruce Martin

Biomedical Engineering

Using a computational model of bone adaptation, we investigated the long-term ability of bisphosphonates to minimize proximal bone loss that is associated with stress shielding in the tibia after long-stemmed total knee arthroplasty (TKA). When invoking bisphosphonate effects, the remodeling activity was suppressed, and the resorption size was reduced. Compared with the untreated simulation, bisphosphonate slowed the rate of bone loss after TKA (42% reduction in bone loss at 1 year). Activating the drug 3 months before the surgery reversed bone loss associated with the reduction in such activities as walking, but it did not provide any substantial benefit in …

Continuing Evolution Of Aerodynamic Concept Development Using Collaborative Numerical And Experimental Evaluations, Russell M. Cummings, Scott A. Morton

Aerospace Engineering

Traditionally, computational predictions and experimental evaluations of aerodynamic concepts have been conducted separately, with little collaboration other than post priori comparisons of results. This has led to distrust and even antagonism between the computational and the experimental communities. These difficulties probably began when early computational fluid dynamic practitioners boasted that wind tunnels would become secondary in aerodynamic concept development within a few short years, a prediction that has not come true. On the contrary, it is believed that a great deal of synergy can be cultivated when computational and experimental evaluations are conducted in an integrative fashion. A variety of …

Critical Hypersonic Aerothermodynamic Phenomena, John J. Bertin, Russell M. Cummings

Aerospace Engineering

The challenges in understanding hypersonic flight are discussed and critical hypersonic aerothermodynamics issues are reviewed. The ability of current analytical methods, numerical methods, ground testing capabilities, and flight testing approaches to predict hypersonic flow are evaluated. The areas where aerothermodynamic shortcomings restrict our ability to design and analyze hypersonic vehicles are discussed, and prospects for future capabilities are reviewed. Considerable work still needs to be done before our understanding of hypersonic flow will allow for the accurate prediction of vehicle flight characteristics throughout the flight envelope from launch to orbital insertion.

Renewable Materials And Construction Waste Management, Samuel A. Vigil

Civil and Environmental Engineering

No abstract provided.

Renewable Energy, Samuel A. Vigil

Civil and Environmental Engineering

No abstract provided.

Comprehensive Analysis Of The Relationship Between Real-Time Traffic Surveillance Data And Rear-End Crashes On Freeways, Anurag Pande, Mohamed Abdel-Aty

Civil and Environmental Engineering

Rear-end collisions are the single most frequent type of crash on freeways. Their impact on freeway operation is also most noticeable because almost all of them occur during periods of medium to heavy demand. Preliminary explorations of average traffic speeds before a crash measured at loop detector stations surrounding the crash location showed that rear-end crashes can be placed into two mutually exclusive groups: first, those that occur under extended congestion and, second, those that occur with relatively free-flow conditions prevailing 5 to 10 min before the crash. With loop detector data preceding these two groups of rear-end crashes contrasted …

Design Of A Low-Cost Acoustic Modem For Moored Oceanographic Applications, Bridget Benson, Grace Chang, Derek Manov, Brian Graham, Ryan Kastner

Electrical Engineering

This paper discusses the current state of the art systems of real time telemetry on oceanographic moorings and describes the design requirements for making acoustic modem data telemetry a more widely used form of data telemetry for moored oceanographic applications. We present the design of a low cost ‘mooring modem’ and the results of an initial pool test for its prototype. Based on these results, we describe how the mooring modem meets the design requirements for moored oceanographic applications by looking at how it meets the requirements for a specific mooring example – the SB CHARM. We conclude by presenting …

Water Conservation And Wastewater Treatment, Samuel A. Vigil

Civil and Environmental Engineering

No abstract provided.

The Effect Of Reflow Profile On Snpb And Snagcu Solder Joint Shear Strength, Jianbiao Pan, Brian J. Toleno, Tzu-Chien Chou, Wesley J. Dee

Industrial and Manufacturing Engineering

Purpose –The purpose of this work is to study the effect of the reflow peak temperature and time above liquidus on both SnPb and SnAgCu solder joint shear strength.

Design/methodology/approach –Nine reflow profiles for Sn3.0Ag0.5Cu and nine reflow profiles for Sn37Pb have been developed with three levels of peak temperature (230°C, 240°C, and 250°C for Sn3.0Ag0.5Cu; and 195°C, 205°C, and 215°C for Sn37Pb) and three levels of time above solder liquidus temperature (30, 60, and 90 s). The shear force data of four different sizes of chip resistors (1206, 0805, 0603, and 0402) are compared across the different …

Osteon Interfacial Strength And Histomorphometry Of Equine Cortical Bone, Robert F. Bigley, Lanny V. Griffin, Lisa Christensen, Ryan Vandenbosch

Biomedical Engineering

The interfacial strength of secondary osteons from the diaphysis of the Thoroughbred equine third metacarpal was evaluated using the fiber pushout test. The pushout was performed on 300–500 mm sections of 4x4x15mm bone blocks machined from four anatomic regions of the cortex. Pushout strength was evaluated from proximal to distal location within the diaphysis on four osteon types classified under polarized light on adjacent histologic sections from each block. The shear strength of the interfaces were estimated from shear lag theory. Differences were found in the interfacial strength of osteons based on appearance under polarized light with bright field having …

A Simplified Model For Ploughing Forces In Turning, Daniel Waldorf

Industrial and Manufacturing Engineering

This paper aims to provide experimental data in support of a modified theoretical model for quantifying the effect of cutting tool edge geometry on machining forces. A previously published slip-line model is simplified and extended to the case of turning. Several sets of machining experiments were run with custom-fabricated cutting inserts of varying edge hone radius and chamfer geometry. Cutting forces were measured using a dynamometer during cutting. Results show that varying edge geometry can have a major effect on cutting forces. The developed model effectively captures the edge phenomenon and its effect on cutting forces and also offers a …

Dynamic Modeling Of Microclimate And Environmental Control Strategies In A Greenhouse Coupled With A Heat Pump System, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The purpose of this study was to develop and validate a dynamic simulation model to be employed in accurate prediction of microclimate in a greenhouse as a function of dynamic environmental factors. The model has options to evaluate the effects of location, time of the year, orientation, single and double polyethylene glazings, conventional and heat pump heating and cooling systems, open and confined greenhouse systems, CO₂ enrichment, variable shading, and the use of night curtains. Conventional gas furnace and evaporative cooling, respectively, provided heating and cooling in the conventional system. In the heat pump systems, gas-fired heat pump units …