Engineering Commons^™

Characteristics Of Pump Performance In Major Irrigated Areas Of California, Sierra A. Orvis Layous, Charles M. Burt, Luis P. Urrestarazu

BioResource and Agricultural Engineering

Well pump tests (12,876) in three Central California groundwater basins were characterized and described according to their spatial distribution. The average overall pumping plant efficiency (wire-water, not including column losses and velocity head) was about 56%. Characteristics such as drawdown, total dynamic heads, kW, and flow rate vary greatly between pumps within and between sub-basins. This is the first well pump characterization of its type in California, although irrigation pump tests have been conducted for over 70 years in California. This paper provides a summary of the spatial variation of well pump performance and characteristics.

The Irrigation Sector Shift From Construction To Modernization: What Is Required For Success?, Charles M. Burt

BioResource and Agricultural Engineering

External pressures related to environmental protection, commodity prices, energy availability, larger populations, and climate change have combined to require an immediate and substantial improvement in agricultural irrigation performance. Worldwide progression towards modernized irrigation projects has been uneven and slower than desired, but decades of irrigation modernization development have clarified certain requirements for success, as well as illuminated indicators of project failure. Of particular importance are required shifts within the state and national irrigation bureaucracies, as well as universities.

Motor Reference, Mohamed Grissa

BioResource and Agricultural Engineering

This document contains summary information about the following motor topics:

• Motor selection information
• AC induction motors
• Inverter duty motors
• Variable frequency drives
• Motor losses
• Troubleshooting

The information contained in this document was gathered from a variety of online, interview, and print sources, including NEMA specifications, with support from the California Energy Commission (CEC) PIER Program.

Drip Irrigation System Cost Sharing By Irrigation Districts For Water Conservation, Charles M. Burt

BioResource and Agricultural Engineering

Government and irrigation district cost sharing programs have often included financial support for the installation of drip/micro irrigation systems. These programs seek advantages that might include improved crop yield, less applied water, and a reduction in subsurface drainage water and surface tailwater. They may also seek to reduce water consumption. The actual results have been shown to vary by district, hydrology, and crop.

It is true that drip systems in California, on average, have good Distribution Uniformities (DU) of irrigation water – meaning that there are only minor differences between the depths of water received by various plants throughout a …

Test 2012a: New Holland Workmaster 55, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Probabilistic Stress Analysis Of Circular Fins Of Different Profiles, Sridhar Madhira Venkata

ETD Archive

The temperature distribution and thermal Stresses induced by a temperature difference for steady state heat transfer in silicon carbide (SiC) ceramic tube heat exchanger with circular fins was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties in the performance parameters. Cumulative distribution functions and sensitivity factors were computed for Hoop and Radial stresses due to the structural and thermodynamic random variables. These results are used to identify the most critical design variables in order to optimize the design and make it cost effective. The probabilistic analysis leads to the selection of the …

Computational Models Of Chemical Systems Inspired By Braess’ Paradox, Dante Lepore, Carl Barratt, Pauline Schwartz

Chemistry and Chemical Engineering Faculty Publications

Systems chemistry is a new discipline which investigates the interactions within a network of chemical reactions. We have studied several computational models of chemical systems inspired by mathematical paradoxes and have found that even simple systems may behave in a counterintuitive, non-linear manner depending upon various conditions. In the present study, we modeled a set of reactions inspired by one such paradox, Braess’ paradox, an interesting phenomenon whereby the introduction of additional capacity (e.g. pathways) in some simple network systems can lead to an unexpected reduction in the overall flow rate of “traffic” through the system. We devised several chemical …

Nitric Oxide-Generating Silicone As A Blood-Contacting Biomaterial, Kagya Amoako

Mechanical and Industrial Engineering Faculty Publications

Coagulation upon blood-contacting biomaterials remains a problem for short and long-term clinical applications. This study examined the ability of copper(II)-doped silicone surfaces to generate nitric oxide (NO) and locally inhibit coagulation. Silicone was doped with 3-micron copper (Cu(0)) particles yielding 3 to 10 weight percent (wt%) Cu in 70-μm thick Cu/Silicone polymeric matrix composites (Cu/Si PMCs). At 3, 5, 8 and 10 wt% Cu doping, the surface expression of Cu was 12.1 ± 2.8%, 19.7 ± 5.4%, 29.0 ± 3.8%, and 33.8 ± 6.5% respectively. After oxidizing Cu(0) to Cu(II) by spontaneous corrosion, NO flux, JNO (mol*cm−2*min−1), as measured by …

Evaluating "Independent" Assessment Of Capstone Projects By Mechanical Engineering Students In Dit, Kevin Delaney

Conference Papers

A review has recently been conducted to evaluate the process from the perspective of both students and staff with a view to determining whether or not this structure should be continued with. This paper documents the rationale behind the concept, the logistical challenges, and an analysis of the feedback received from both students and staff as part of the review. In addition, future plans to improve the fairness, consistency and transparency of the assessment process for such projects are outlined.

An Alternative Approach To Integrating Plasticity Relations, Richard Becker

United States Army: Publications

A new plasticity integration algorithm is proposed based upon observations from the closed form integration of a generalized quadratic yield function over a single time step. The key to the approach is specification of the normal to the plastic flow potential as a function of the current state and strain increment. This uniquely defines the direction of the stress tensor for a convex, non-faceted flow potential. The stress magnitude and plastic strain increment are computed to satisfy the yield function. A non-quadratic, isotropic, associative flow model is coded to demonstrate accuracy and time step convergence following a step change in …

Nanoindentation Characterization Of Deformation And Failure Of Aluminum Oxynitride, J. J. Guo, K. Wang, T. Fujita, J. W. Mccauley, J. P. Singh, M. W. Chen

United States Army: Publications

A systematic study of the mechanical deformation and failure of transparent ceramic aluminum oxynitride (AlON) has been conducted using a depth-sensitive nanoindentation technique combined with transmission electron microscopy (TEM) and Raman spectroscopy. Although discrete displacement bursts appear in the load–depth profiles at high applied forces, a detectable high-pressure phase transition has not been found by means of micro-Raman spectroscopy and TEM. Instead, a high density of dissociated (1 1 0) dislocations can be observed underneath the nanoindenters, suggesting that extensive plastic deformation takes place in the brittle ceramic at high contact pressures. Moreover, nanoindentation-induced micro-cracks oriented along well-defined crystallographic planes …

Development Of A Friction Testing Apparatus For Demoulding Force Prediction, Kevin Delaney, David Kennedy, G. Bissacco

Conference Papers

Friction between replication tools and replicated parts determines the force required to demould the part and also the stresses which develop in both the tool and the part during the demoulding process. Standardized equipment and procedures have been developed which strive to improve the repeatability and reproducibility of friction tests. Specific test standards, describing sled-type tests, include JIS K 7125, ISO 8295 and ASTM D1894. However these tests do not produce results which are representative of the conditions typically found within replication tools such as injection moulds or embossing tools. This paper reviews how this challenge has been addressed by …

Influence Of Initial Mean Helicity On Homogeneous Turbulent Shear Flow, Frank G. Jacobitz, Kai Schneider, Wouter J. T. Bos, Marie Farge

School of Engineering: Faculty Scholarship

Helicity statistics are studied in homogeneous turbulent shear flow. Initial mean helicity is imposed on an isotropic turbulence field using a decomposition of the flow into complex-valued helical waves. The initial decay of the turbulent kinetic energy is weakened in the presence of strong mean helicity, consistent with an analytic analysis of the spectral tensor of velocity correlations. While exponential growth of the mean turbulent kinetic energy is obtained, the mean helicity decays. Probability distribution functions (PDFs) of helicity are skewed and show that the imposed mean helicity prevails throughout the simulations. A wavelet-based scale-dependent analysis shows a trend to …

Effect Of Substrate Composition And Alignment On Corneal Cell Phenotype, Donna Phu '09, Lindsay S. Wray '08, Robert V. Warren '10, Richard C. Haskell, Elizabeth J. Orwin

All HMC Faculty Publications and Research

Corneal blindness is a significant problem treated primarily by corneal transplants. Donor tissue supply is low, creating a growing need for an alternative. A tissue-engineered cornea made from patient-derived cells and biopolymer scaffold materials would be widely accessible to all patients and would alleviate the need for donor sources. Previous work in this lab led to a method for electrospinning type I collagen scaffolds for culturing corneal fibroblasts ex vivo that mimics the microenvironment in the native cornea. This electrospun scaffold is composed of small-diameter, aligned collagen fibers. In this study, we investigate the effect of scaffold nanostructure and composition …

Toward Increasing Performance And Efficiency In Gas Turbines For Power Generation And Aero-Propulsion Unsteady Simulation Of Angled Discrete-Injection Coolant In A Hot Gas Path Crossflow, Perry L. Johnson

HIM 1990-2015

This thesis describes the numerical predictions of turbine film cooling interactions using Large Eddy Simulations. In most engineering industrial applications, the Reynolds-Averaged Navier-Stokes equations, usually paired with two-equation models such as k-Greek lowercase letter epsilon] or k-Greek lowercase letter omega], are utilized as an inexpensive method for modeling complex turbulent flows. By resolving the larger, more influential scale of turbulent eddies, the Large Eddy Simulation has been shown to yield a significant increase in accuracy over traditional two-equation RANS models for many engineering flows. In addition, Large Eddy Simulations provide insight into the unsteady characteristics and coherent vortex structures of …

High Frequency Thermally Actuated Single Crystalline Silicon Micromechanical Resonators With Piezoresistive Readout, Amir Rahafrooz

Electronic Theses and Dissertations

Over the past decades there has been a great deal of research on developing high frequency micromechanical resonators. As the two most common and conventional MEMS resonators, piezoelectric and electrostatic resonators have been at the center of attention despite having some drawbacks. Piezoelectric resonators provide low impedances that make them compatible with other low impedance electronic components, however they have low quality factors and complicated fabrication processes. In case of electrostatic resonators, they have higher quality factors but the need for smaller transductions gaps complicates their fabrication process and causes squeezed film damping in Air. In addition, the operation of …

Hybrid Sensing And Adaptive Control For Direct Brain Actuation Of Artificial Limbs, Christopher Aasted

Electronic Theses and Dissertations

Developing a non-invasive direct brain control of artificial limbs is both challenging and desirable. Such a sensory and control system, if successful, will have a profound impact on the disabled. In this dissertation, we present the design and development of a non-invasive, hybrid sensory system, which uses near-infrared spectroscopy (NIRS) and electroencephalography (EEG) to measure brain activity with simultaneous electromyography (EMG) to provide feedback data in a healthy limb. Through the combination of these sensory techniques, we have successfully trained a control system capable of mapping brain activity onto muscle actuation. The design of a control algorithm capable of automatic …

Cottonwood Management Plan/Programmatic Environmental Assessment Proposed Implementation Of A Cottonwood Management Plan Along Six Priority Segments Of The Missouri River

United States Army Corps of Engineers, Omaha District

The U.S. Army Corps of Engineers (Corps) proposes to preserve existing stands and reestablish new stands of plains cottonwood (Populus deltoides) at selected public/government lands along the Missouri River in accordance with the Cottonwood Management Plan (CMP). The Proposed Action is the implementation of the CMP. The goal of the plan is to be a living document that preserves, creates, or restores cottonwood habitats along the Missouri River and meets the requirements of the USFWS 2003 Amended Biological Opinion (BiOp) concerning the bald eagle (Haliaeetus leucocephalus). The principal immediate focus of the CMP includes measures in …

Missouri River Recovery Program: 2009 Spring Pulse And Rises Drainage Monitoring And Evaluation

United States Army Corps of Engineers, Omaha District

Spring pulse releases for the benefit of the endangered pallid sturgeon were planned for March and May 2009 to mimic historic natural spring rises that occurred on the Missouri River before the closure of the main stem dams. The March spring pulse from Gavins Point Dam was not released in 2009 due to high downstream flows and the possibility of flow-limit violations. A 6.1 -kcfs May spring pulse was released in 2009.

The May spring pulse was monitored at 44 sites along the Missouri River. Nineteen of these were interior-drainage sites that were monitored for possible socioeconomic impacts to landowners. …

2010/11 Research, Development, And Activities, College Of Engineering And Applied Sciences

Electrical and Computer Engineering Newsletter

• Center for Advanced Smart Sensors and Structures (CASSS)
• Vehicular Ad Hoc Network Augmenting GPS Systems
• In-Flight Discreet Wireless Communication System
• Dual-Use Ground Vehicle Condition-Based Maintenance
• Neurobiology Engineering Laboratory
• CEAS Students Win Stryker Challenge!
• Earth Today iPhone Application for JPL’s Earth Sciences Directorate

A Possible Pathway For High School Science In A Stem World, Cary Sneider

Publications

Today‘s high school science teachers find themselves in a period of transition. For the past decade there have been calls for replacing a narrow focus on science education—the traditional courses in physics, chemistry, biology, and Earth and space science—with a broader curriculum on STEM (that is, the four allied fields of science, technology, engineering, and mathematics). However, at present there are no guidelines on what that broader curriculum should include or how it should be designed, and the gulf that has separated science and mathematics seems as wide as ever, despite decades of efforts to bridge the two disciplines. Next …

Mapping Engineering Concepts For Secondary Level Education, Jenny L. Daugherty

Publications

Much of the national attention on science, technology, engineering, and mathematics (STEM) education tends to concentrate on science and mathematics, with its emphasis on standardized test scores. However as the National Academy of Engineering Committee on K-12 Engineering Education stressed, engineering can contribute to the development of an effective and interconnected STEM education system (Katehi, Pearson, & Feder, 2009). In addition, engineering can provide authentic learning contexts for science, technology, and mathematics. Numerous K-12 engineering initiatives have emerged across the U.S. developing curriculum and conducting teacher professional development (Brophy, Klein, Portsmore, & Rogers, 2008). The focus of pre-college engineering education …

Mapping Engineering Concepts For Secondary Level Education, J. L. Daugherty

Publications

No abstract provided.

Engineering Design Thinking And Information Gathering Final Report, Nathan Mentzer

Publications

The objective of this research was to explore the relationship between information access and design solution quality of high school students presented with an engineering design problem. This objective is encompassed in the research question driving this inquiry: How does information access impact the design process? This question has emerged in the context of an exploratory DR-K12 grant project titled, Exploring Engineering Design Knowing and Thinking as an Innovation in STEM Learning. The research work presented here has expanded the data set developed in the DR-K12 and examined the larger data set with a focus on how information access impacts …

Understanding Of Student Task Interpretation, Design Planning, And Cognitive Strategies During Engineering Design Activities In Grades 9-12, Oenardi Lawanto

Publications

The objective of this study was to describe the task interpretation of students engaged in a design activity and determine the extent to which students translate their understanding of their design task to their planning and cognitive strategies. Twenty-nine students at one Colorado high school participated in this study. Students worked individually in the Architectural Design class (n=7), and in teams in the Robotics Design class (n=22). To capture students’ perceptions of their understanding of the task, planning strategies, and cognitive strategies, the Engineering Design Questionnaire (EDQ) was used. The development of the EDQ was guided by Butler and Cartier’s …

Design Problems For Secondary Students, David H. Jonassen

Publications

Are there different kinds of design problems? According to Brown and Chandrasekaran (1989), Class 1 design problems are open-ended, non-routine creative activities where the goals are ill-structured, and there is no effective design plan specifying the sequence of actions to take in producing a design model. Class 2 problems use existing, well-developed design and decomposition plans (e.g. designing a new automobile). Class 3 designs are routine where design and decomposition plans are known as well as customary actions taken to deal with failures (e.g., writing a computer program). Jonassen (2011) argued that problems vary in terms of structuredness, complexity, and …

Integrating Engineering Design Challenges Into Secondary Stem Education, Ronald L. Carr

Publications

Engineering is being currently taught in the full spectrum of the P-12 system, with an emphasis on design-oriented teaching (Brophy, Klein, Portsmore, & Rogers, 2008). Due to only a small amount of research on the learning of engineering design in elementary and middle school settings, the community of practice lacks the necessary knowledge of the trajectory of students' learning progressions towards design mastery and expertise and the appropriateness of otherwise established design pedagogies. The issue is even more pressing since many states are embedding engineering into their standards without a clear notion of how engineering (often conceptualized as design) works …

Building A Framework For Engineering Design Experiences In Stem: A Synthesis, Cameron D. Denson

Publications

Since the inception of the National Center for Engineering and Technology Education in 2004, educators and researchers have struggled to identify the necessary components of a “good” engineering design challenge for high school students. In reading and analyzing the position papers on engineering design many themes emerged that may begin to form a narrative for engineering design in a high school setting. Before educators can provide a framework for engineering design in STEM courses, four questions need to be answered: (a) To what degree should engineering design challenges be open-ended or well-structured? (b) What are the relationships between engineering design …

Accidental Releases Of Hazardous Materials And Relevance To Terrorist Threats At Industrial Facilities, Laura J. Steinberg, Nicholas Santella

Civil and Environmental Engineering - All Scholarship

Hazardous material releases, some with serious consequences, are a common occurrence in the U.S. Of late, the hazards posed by releases caused by terrorist attacks or natural disasters have been of particular concern. Although terrorism directed at hazardous material handling industries within the U.S. has not yet resulted in a significant incident, there is much recent experience with serious accidental releases resulting from natural disasters. Case studies are developed from a number of recent natural disasters and severe weather events that resulted in large releases of hazardous materials. These case studies are used to illustrate parallels between the risks posed …

Spatial And Temporal Patterns Of Mercury Accumulation In Lacustrine Sediments Across The Laurentian Great Lakes Region, Paul E. Drevnick, Daniel R. Engstrom, Charles T. Driscoll, Edward B. Swain, Steven J. Balogh

Civil and Environmental Engineering - All Scholarship

Data from 104 sediment cores from the Great Lakes and “inland lakes” in the region were compiled to assess historical and recent changes in mercury (Hg) deposition. The lower Great Lakes showed sharp increases in Hg loading c. 1850-1950 from point-source water dischargers, with marked decreases during the past half century associated with effluent controls and decreases in the industrial use of Hg. In contrast, Lake Superior and inland lakes exhibited a pattern of Hg loading consistent with an atmospheric source - gradual increases followed by recent (post-1980) decreases. Variation in sedimentary Hg flux among inland lakes was primarily attributed …