Engineering Commons^™

East Bay Energy Consortium, Joint Committee Workshop At The Bristol Town Hall, Burnside Building, February 24, 2010, Meeting Notes, East Bay Energy Consortium

East Bay Energy Consortium Meeting Minutes

No abstract provided.

East Bay Energy Consortium Joint Committee Workshop At The Bristol Town Hall, Burnside Building, February 24, 2010, Meeting Notes, East Bay Energy Consortium

East Bay Energy Consortium Meeting Minutes

No abstract provided.

Reducing The Cost Of Pumping Irrigation Water, Derrel L. Martin, William L. Kranz, Tom W. Dorn, Steve R. Melvin, Alan J. Corr

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Irrigation accounts for a large portion of the energy used in Nebraska agriculture. The cost to pump irrigation water depends on the type of energy used to power the pumping unit. This document describes a method to estimate the cost of pumping water and to compare the amount of energy used to that for a well maintained and designed pumping plant. The results can help determine the feasibility of repairing the pumping plant.

Frequency Response And Gain Enhancement Of Solid-State Impact-Ionization Multipliers (Sims), Joshua L. Beutler

Theses and Dissertations

A study of the frequency response and gain of Solid-state the Impact-ionization Multiplier (SIM). The SIM generates current gain via impact ionization also known as avalanche gain. The SIM provides low noise amplification from an arbitrary current source. In the case of this study, current sources consisted of photodiodes optimized for a particular wavelength of light. The SIM is fabricated from silicon and enjoys the low noise, low carrier transit time advantages of conventional silicon impact ionization devices while amplifying current from a photodiode of a different material. This is advantageous because ideal detection and multiplication regions cannot always be …

Colorado River Water: Mexico's Perspective On The Ongoing Negotiations, Mario López Pérez

US-Mexico Negotiations on Improved Colorado River Management: An Update (February 19)

Presenter: Mario López, Engineering and Technical Standards Manager, National Water Commission of México

53 slides

Agenda: Us-Mexico Negotiations On Improved Colorado River Management: An Update, University Of Colorado Boulder. Natural Resources Law Center, Western Water Policy Program, Colorado Water Conservation Board

US-Mexico Negotiations on Improved Colorado River Management: An Update (February 19)

The United States and Mexico are currently negotiating an international accord on a variety of Colorado River water matters, including the prospects for new water projects, conservation efforts, and operational improvements. Participants are invited to hear an update on these efforts from individuals directly involved in the negotiations, including Mario López Pérez, Engineering and Technical Standards Manager in the National Water Commission of México, who is responsible for binational water issues with the USA, Guatemala and Belize.

Performance Of Self-Encoded Spread Spectrum Under Worst-Case Jamming, Casey L. Deyle

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

Performance of Self-Encoded Spread Spectrum Under Worst-Case Jamming Casey Deyle, M.S University of Nebraska 2009 Advisor: Lim Nguyen Spread Spectrum Communications uses m-sequences (sometimes referred to as Pseudo Noise or PN sequences) modulated with a data signal to create a transmission signal that takes up more bandwidth than the original information signal. Self-Encoded Spread Spectrum (SESS) uses spreading codes generated by the transmitted signal, eliminating the need to synchronize m-sequences between the transmitter and receiver, thus making the channel more secure. This paper will discuss the performance of SESS system in Additive White Gaussian Noise (AWGN) and Rayleigh fading channels, …

Coset: Cooperative Set Last Level Caches, Dongyuan Zhan, Hong Jiang, Sharad Seth

School of Computing: Technical Reports

The speed gap between processors and DRAM remains a crit-ical performance bottleneck for contemporary computer systems, which necessitates an effective management of last level caches (LLC) to minimize expensive off-chip accesses. However, because all sets in a conventional set-associative cache design are statically assigned an equal number of blocks, the LLC capacity utilization can drastically diminish when the cache actually exhibits non-uniform capacity demands across the sets. To reveal the wide exis-tence of set-level non-uniformity of capacity demand in real appli-cations, this technical report first establishes an accurate metric for measuring individual sets’ capacity demands by developing a group of …

Extracellular Matrix Based Substrates For Propagation Of Human Pluripotent Stem Cells, Sheena Abraham

Theses and Dissertations

In human pluripotent stem cell (hPSC) research and applications, the need for a culture system devoid of non-human components is crucial. Such a system should exhibit characteristics observed in conventional culture systems that have used mouse embryonic fibroblast feeders for hPSC self renewal without the requirement of excessive supplementation with growth factors. To achieve this, we focused on the identification and characterization of extracellular matrix (ECM) substrates for hPSC propagation. ECM substrates derived from mouse and human fibroblasts were assessed for their ability to support self-renewal of hPSCs. Characterization of hPSCs on ECM-based substrates demonstrated maintenance of pluripotent characteristics based …

Tunneling Between Carbon Nanofiber And Gold Electrodes, Toshishige Yamada, Tsutomu Saito, Makoto Suzuki, Patrick Wilhite, Xuhui Sun, Navid Akhavantafti, Drazen Fabris, Cary Y. Yang

Electrical and Computer Engineering

In a carbon nanofiber (CNF)-metal system such as a bridge between two gold electrodes, passing high current (current stressing) reduces the total resistance of the system (CNF resistance RCNF plus contact resistance Rc) by orders of magnitude. The role of current stressing is modeled as a reduction in the interfacial tunneling gap with transport characteristics attributed to tunneling between Au and CNF. The model predicts a reduction in Rc and gradual disappearance of the nonlinearity in the current-voltage (I-V) characteristics as Rc decreases. These results are consistent with measured I-V behavior.

Fast Block Matching Using Minkowski's Inequality, Jim Zong-Chang Lai, Yi-Ching Liaw, Shih-An Fong

Journal of Marine Science and Technology–Taiwan

In this paper, we present a fast block matching algorithm by making use of the Minkowski’s inequality. Combined with other fast block matching algorithms, our method can further reduce the computational complexity significantly with little PSNR degradation. Compared to the full search block matching algorithm, our approach can reduce the computing time by a factor of 6.4 to 21.5. Compared to MSEQ, which is a wellknown block matching algorithm preserving global optimality, our method can further reduce the corresponding computing time in average by 32.4%. The combination of our algorithm and the predictive search area approach for block motion estimation …

Melnikov Analysis Of A Ship's Stability With Water-On-Deck, Ying-Guang Wang

Journal of Marine Science and Technology–Taiwan

The nonlinear ship rolling motion with water-on-deck in regular beam waves is studied by utilizing a global geometric method. A ship stability criterion based upon the Melnikov function is obtained to provide an upper bound on the domain of the potential chaotic rolling motion. Phase plane diagrams and Poincare maps are used to validate the ship stability criterion obtained in this article.

A Delay-Dependent Approach To Robust Stability For Uncertain Stochastic Neural Networks With Time-Varying Delay, Chien-Yu Lu, Chin-Wen Liao, Koan-Yuh Chang, Wen-Jer Chang

Journal of Marine Science and Technology–Taiwan

This paper investigates the global delay-dependent robust stability in the mean square for uncertain stochastic neural networks with time-varying delay. The activation functions are assumed to be globally Lipschitz continuous. Based on a linear matrix inequality approach, globally delay-dependent robust stability criterion is derived by introducing some relaxation matrices which, when chosen properly, lead to a less conservative result. Two numerical examples are given to illustrate the effectiveness of the method.

Corner Effects In Deep Excavations-Establishment Of A Forecast Model For Taipei Basin T2 Zone, Chao-Hui Wu, Chang-Yu Ou, Ningchien Tung

Journal of Marine Science and Technology–Taiwan

This study attempts to establish a novel model for forecasting wall deformation and ground surface settlement of deep excavations. The model is developed by considering the corner effect and examining the data from relevant case histories. The study is specifically limited to the construction works in the T2 zone of the Taipei Basin. The following results were obtained: (1) The maximum wall deformation during each excavation step was approximately 0.2%-0.5% of the excavation depth, and was influenced by the corner effect. (2) The maximum ground surface settlement took place approximately at the center of the wall; and settlements at the …

Shape Optimization Of One-Chamber Mufflers With Reverse-Flow Ducts Using A Genetic Algorithm, Min-Chie Chiu

Journal of Marine Science and Technology–Taiwan

Shape optimization on mufflers within a limited space is essential for industry where the equipment layout is occasionally tight and the available space for a muffler is limited for maintenance and operation purposes. To proficiently enhance the acoustical performance within a constrained space, the selection of an appropriate acoustical mechanism and optimizer becomes crucial. A one-chamber muffler hybridized with reverse-flow ducts which can visibly increase the acoustical performance is rarely addressed; therefore, the main purpose of this paper is to numerically analyze and maximize the acoustical performance of this muffler within a limited space. In this paper, the four-pole system …

Optimal Heating And Energy Management For Slabs In A Reheating Furnace, Wei-Hsin Chen, Mu-Rong Lin, Tzong-Shyng Leu

Journal of Marine Science and Technology–Taiwan

Optimal heating for slabs in a reheating furnace is investigated numerically to aid in managing energy consumption of the reheating furnace in a hot strip mill, where an arctangent function is applied as the heating curve. Particular attention is paid to the relationship among the temperature uniformity, discharging target temperature and retention time of the slabs. The results indicate that the temperature difference between the slab surface and the core increases rapidly in the initial period and the maximum value of the temperature difference is close to the inflection point of the heating curve. After that, the internal temperature tends …

Estimation Model Of Transformer Iron Loss Using Neural Network, Tai-Ken Lu, Chien-Ta Yeh, Min-Doon Dirn

Journal of Marine Science and Technology–Taiwan

When we want to calculate the transformer iron loss in operation, in addition to considering the nonlinear hysteretic phenomenon of transformer itself and the natural unbalanced characteristic, the actual situation that the transformer is operated under three phase unbalance state should also be considered. This results in very non-regular change of the transformer iron loss, and the accuracy of the polynomial model that is commonly used to estimate the iron loss of the transformer in the past is thus reduced. Since neural network has parallel processing capability, which can process highly nonlinear function problem, hence, in this study, we try …

Closed-Form Solutions Of Large Deflection For A Guyed Cantilever Column Pulled By An Inclination Cable, Jong-Dar Yau

Journal of Marine Science and Technology–Taiwan

Geometric non-linearity becomes an issue of great concern that cannot be overlooked in the analysis of cable-supported structures since their material properties may be in an elastic range but they exhibit nonlinear behavior when loaded. This study intends to present an analytical approach for analyzing the large deflection behavior of a guyed column pulled by a pre-tensioned cable at different stages of installation. The column is assumed to be naturally straight and inextensible, and each cable is modeled as an equivalent tensile bar neglecting the sag effect due to self-weight. Based on an elliptic integral formulation, closed-form solutions are derived …

An Effective Method In Bem For Potential Problems Of Thin Bodies, Yao-Ming Zhang, Yan Gu

Journal of Marine Science and Technology–Taiwan

The study of the effective methods dealing with problems with thin domains is an important and a difficult issue in boundary element method (BEM). For the special structures of thin bodies, the singular and nearly singular integrals often occur simultaneously in boundary integral equations (BIEs). Therefore, the conventional boundary element method (CBEM) is invalid to obtain accurate results. This paper based on the indirect variable regularized BIEs of plane potential problems, and a nonlinear variable transformation is introduced in order to improve the rapid variations of nearly singular integrals. By doing these, the boundary singular and nearly singular integrals can …

Experimental Study Of Deformation Behavior And Fatigue Life Of Aisi 304 Stainless Steel Under An Asymmetric Cyclic Loading, Yung-Chuan Chiou

Journal of Marine Science and Technology–Taiwan

In this study, the cyclic deformation behavior and fatigue life of AISI 304 stainless steel with or without mean strains were studied experimentally. In the case of fully reversal cyclic straining, it is found that there is no virtually difference between the cyclic stress response curves in tension and in compression at strain amplitude of higher than 0.30%. At the controlled strain amplitude of 0.25% and 0.30%, the two cyclic stress response curves are separated quite widely. The degree of asymmetry can be attributed to the anisotropic behavior of AISI 304 stainless steel. Further, the experimental results indicate that AISI …

Effect Of Commutation Failures On Torsional Vibrations Of A Turbine Generator Nearby An Hvdc Link, Chi-Hshiung Lin

Journal of Marine Science and Technology–Taiwan

For an HVDC system, it is studied the torsional vibrations induced on the inverter side turbine generators due to a rectifier side ac faults. It is found there may be up to several times difference in the torsional torques induced at the turbine shafts and blades for the same fault, depending on the inverter commutation behavior. Further, if a single-phase-to-ground fault takes place with the commutation failure, it might cause a more serious impact on the turbine generator unit than a threephase-to-ground fault without commutation failure.

The Effect Of Ace Inhibition On The Pulmonary Vasculature In Combined Models Of Chronic Hypoxia And Pulmonary Arterial Banding In Sprague Dawley Rats, Shanelle Clarke, Shelley Baumgardt, Robert C. Molthen

Biomedical Engineering Faculty Research and Publications

Microfocal CT was used to image the pulmonary arterial (PA) tree in rodent models of pulmonary hypertension (PH). CT images were used to measure the arterial tree diameter along the main arterial trunk at several hydrostatic intravascular pressures and calculate distensibility. High-resolution planar angiographic imaging was also used to examine distal PA microstructure. Data on pulmonary artery tree morphology improves our understanding of vascular remodeling and response to treatments. Angiotensin II (ATII) has been identified as a mediator of vasoconstriction and proliferative mitotic function. ATII has been shown to promote vascular smooth muscle cell hypertrophy and hyperplasia as well as …

East Bay Energy Consortium Joint Committee Workshop At The Corporate Offices Of Applied Science Associates, February 12, 2010, Meeting Notes, East Bay Energy Consortium

East Bay Energy Consortium Meeting Minutes

No abstract provided.

On The Turbulent Prandtl Number In Homogeneous Stably Stratified Turbulence, Subhas K. Venayagamoorthy, Derek D. Stretch

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, we derive a general relationship for the turbulent Prandtl number Prt for homogeneous stably stratified turbulence from the turbulent kinetic energy and scalar variance equations. A formulation for the turbulent Prandtl number, Prt, is developed in terms of a mixing length scale LM and an overturning length scale LE, the ratio of the mechanical (turbulent kinetic energy) decay time scale TL to scalar decay time scale Tp and the gradient Richardson number Ri. We show that our formulation for Prt is appropriate even for non-stationary (developing) stratified flows, since it does not include the reversible contributions in …

Modeling And Visualization Of Cardiovascular Systems, Thomas Wischgoll

Computer Science and Engineering Faculty Publications

Modeling complex organs, such as the human heart, requires a detailed understanding of the geometric and mechanical properties of that organ. Similarly, the model is only as accurate as the precision of the underlying properties allow. Hence, it is of great importance that accurate measurements of the geometric configuration are available. This paper describes the different steps that are necessary for creating and visualizing such a vascular model, ranging from determining a basic geometric model, gathering statistical data necessary to extend an existing model up to the visualization of the resulting large-scale vascular models.

Predicting Neointimal Hyperplasia In Stented Arteries Using Time-Dependant Computational Fluid Dynamics: A Review, Jonathan Murphy, Fergal Boyle

Articles

This paper reviews the recent literature regarding the time-dependant computational fluid dynamics (CFD) analyses of blood flow through implanted coronary stents. The in vivo processes which result in arterial restenosis are identified. The definition and range of the computationally predicted variables which are believed to stimulate the restenosis processes are evaluated. The reviewed literature is subdivided into effect-based in which the effects of altering the flow model are investigated and design-based in which different geometric stent configurations are compared. Finally, conclusions are made regarding the body of work reviewed and recommendations are provided for future work in this field.

Slides: Energy Development Water Needs Assessment And Water Supply Alternatives And Analysis, Benjamin Harding

The Promise and Peril of Oil Shale Development (February 5)

Presenter: Benjamin Harding, Principal Engineer, AMEC Earth and Environmental

15 slides

Slides: Promise Or Peril: Shale Oil, Energy, And The Region, Chase Huntley

The Promise and Peril of Oil Shale Development (February 5)

Presenter: Chase Huntley, Policy Adviser for Energy & Climate Change, The Wilderness Society

8 slides

Agenda: The Promise And Peril Of Oil Shale Development, University Of Colorado Boulder. Natural Resources Law Center

The Promise and Peril of Oil Shale Development (February 5)

The largest known oil shale deposits in the world are in the Green River Formation, which covers portions of Colorado, Utah, and Wyoming. Fully one-half of the world’s oil shale lies within 150 miles of Grand Junction, Colorado, and about 80% of these reserves are on federal land. Estimates of recoverable reserves in the Green River Formation range from 500 billion to 1.53 trillion barrels. At present consumption rates, this is enough oil to satisfy 100% of U.S. demand for well over 100 years.

Development of oil shale could cause significant impacts on the Colorado Plateau. It would provide for …

Slides: Costs And Benefits Of Oil Shale Development, James T. Bartis

The Promise and Peril of Oil Shale Development (February 5)

Presenter: James T. Bartis, Senior Policy Researcher, Rand Corporation

21 slides