Engineering Commons^™

Isoflurane Modulates Cardiac Mitochondrial Bioenergetics By Selectively Attenuating Respiratory Complexes, Bhawana Agarwal, Ranjan K. Dash, David F. Stowe, Zeljko J. Bosnjak, Amadou K.S. Camara

Biomedical Engineering Faculty Research and Publications

Mitochondrial dysfunction contributes to cardiac ischemia–reperfusion (IR) injury but volatile anesthetics (VA) may alter mitochondrial function to trigger cardioprotection. We hypothesized that the VA isoflurane (ISO) mediates cardioprotection in part by altering the function of several respiratory and transport proteins involved in oxidative phosphorylation (OxPhos). To test this we used fluorescence spectrophotometry to measure the effects of ISO (0, 0.5, 1, 2 mM) on the time-course of interlinked mitochondrial bioenergetic variables during states 2, 3 and 4 respiration in the presence of either complex I substrate K⁺-pyruvate/malate (PM) or complex II substrate K⁺-succinate (SUC) at physiological …

Opportunistic Access In Frequency Hopping Cognitive Radio Networks, Ethan S. Hennessey

Theses and Dissertations

Researchers in the area of cognitive radio often investigate the utility of dynamic spectrum access as a means to make more efficient use of the radio frequency spectrum. Many studies have been conducted to find ways in which a secondary user can occupy spectrum licensed to a primary user in a manner which does not disrupt the primary user's performance. This research investigates the use of opportunistic access in a frequency hopping radio to mitigate the interference caused by other transmitters in a contentious environment such as the unlicensed 2.4 GHz region. Additionally, this work demonstrates how dynamic spectrum access …

Phase Transitions Of Perfluorocarbon Nanoemulsion Induced With Ultrasound: A Mathematical Model, William G. Pitt, Ram N. Singh, Krystian X. Perez, Ghaleb A. Husseini, Daniel R. Jack

Faculty Publications

While ultrasound has been used in many medical and industrial applications, only recently has research been done on phase transformations induced by ultrasound. This paper presents a numerical model and the predicted results of the phase transformation of a spherical nanosized droplet of perfluorocarbon in water. Such a model has applications in acoustic droplet vaporization, the generation of gas bubbles for medical imaging, therapeutic delivery and other biomedical applications. The formation of a gas phase and the subsequent bubble dynamics were studied as a function of acoustic parameters, such as frequency and amplitude, and of the physical aspects of the …

Triplet Ground State Of The Neutral Oxygen-Vacancy Donor In Rutile Tio2, A. T. Brant, Eric M. Golden, Nancy C. Giles, Shan Yang, M. A. R. Sarker, S. Watauchi, M. Nagao, I. Tanaka, D. A. Tryk, A. Manivannan, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) is used to investigate the triplet (S = 1) ground state of the neutral oxygen vacancy in bulk rutile TiO₂ crystals. This shallow donor consists of an oxygen vacancy with two nearest-neighbor, exchange-coupled ³⁺ ions located along the [001] direction and equidistant from the vacancy. The spins of the two trapped electrons, one at each ³⁺ ion, align parallel to give the S = 1 state. These neutral oxygen vacancies are formed near 25 K in as-grown oxidized TiO₂ crystals by illuminating with sub-band-gap 442 nm laser light. The angular dependence of the EPR …

Aircraft Route Optimization For Formation Flight, Jia Xu, Andrew Ning, Geoffrey Bower, Ilan Kroo

Faculty Publications

We quantify the fuel and cost benefits of applying extended formation flight to com- mercial airline operations. Central to this study is the development of a bi-level, mixed integer-real formation flight optimization framework. The framework has two main components: 1) a continuous domain aircraft mission performance optimization and 2) an integer optimization component that selects the best combination of optimized missions to form a formation flight schedule. The mission performance reflects the effects of rolled-up wakes, formation heterogeneity, and formation-induced compressibility. The results show that an airline can use formation flight to reduce fuel burn by 5.8% or direct operating …

Two Bit Circus, Elise Lemle

The Transdisciplinary STEAM+ Journal

Two Bit Circus collaborated with the Girl Scouts of the Greater Los Angeles Area to explore the exciting world of wearable electronics. Over the course of the program, the students explored concepts of introductory electronics while designing and creating their own illuminated fashion piece. The program was held in Montrose, CA in Fall 2013. The students were approximately 10 girls ages seven to 14. The program was held over seven sessions with each session lasting 80 minutes.

Celestial Messenger, Bijian Fan

The Transdisciplinary STEAM+ Journal

This dragon sculpture is embedded with binary code in the form of 1s and 0s, they are generated by light transmission through the holes.

Spannungsfeld, Julian Voss-Andreae

The Transdisciplinary STEAM+ Journal

My design for a sculptural installation for the University of Minnesota’s new Physics and Nanotechnology Building is inspired by a view of the human body through the lens of quantum physics.

The German title of the installation (literally "tension field") originated in physics but is used in contemporary German almost exclusively in a metaphorical sense, implying a dynamic tension, often between polar opposites, that permeates everything in its vicinity.

An Experimental Investigation Of Crumb Rubber Concrete Confined By Fibre Reinforced Polymer Tubes, Osama Youssf, Mohamed Elgawady, Julie E. Mills, Xing Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Due to the known loss of compressive strength experienced by crumb rubber concrete (CRC) compared with conventional concrete, there have been few applications explored to date for the structural use of these materials. This paper describes experimental work conducted to explore the possible future use of CRC for structural columns by evaluating the use of fiber reinforced polymer (FRP) confinement as a means of overcoming the material deficiencies (decreased compressive strength). The results indicated that the use of FRP to confine rubberized concrete effectively negates the decrease in strength and retains the advantages of increased ductility that arise from rubberized …

Hemocompatibility Comparison Of Biomedical Grade Polymers Using Rabbit Thrombogenicity Model For Preparing Nonthrombogenic Nitric Oxide Releasing Surfaces, Hitesh Handa, Terry C. Major, Elizabeth Brisbois, Kagya Amoako, Mark E. Meyerhoff, Robert E. Bartlett

Mechanical and Industrial Engineering Faculty Publications

Nitric oxide (NO) is an endogenous vasodilator as well as natural inhibitor of platelet adhesion/ activation. Nitric oxide releasing (NOrel) materials can be prepared by doping an NO donor species, such as diazeniumdiolated dibutylhexanediamine (DBHD/N2O2), within a polymer coating. The inherent hemocompatibility properties of the base polymer can also influence the efficiency of such NO release coatings. In this study, four biomedical grade polymers were evaluated in a 4 h rabbit model of thrombogenicity for their effects on extracorporeal circuit thrombus formation and circulating platelet count. At the end of 4 h, Elast-Eon E2As was found to preserve 58% of …

Electrochemical Performance Of Si-C Composites Prepared By Discharge-Plasma Assisted Milling, Yu-Long Chen, Ren-Zong Hu, Hui Liu, Wei Sun, Min Zhu

Journal of Electrochemistry

Silicon-carbon (Si-C) composites, with microstructure of multi-scaled Si particles being homogenously dispersed in micro-sized carbon matrix, had been prepared by dielectric barrier discharge plasma assisted two-step milling for the first time. The Si-C composite anode had a discharge capacity of 1259 mAh·g^-1 at the first cycle, while the capacity retained 474 and 396 mAh·g^-1 after 20 and 100 cycles, respectively. Charge-discharge curves and AC impedance response indicated that both silicon and carbon phases in the composite anode were involved during the lithiation/delithiation reactions and the electron transport resistance in the Si-C composite anode was much lower than that …

Development Of Safety Standards For Cubesat Propulsion Systems, Liam Jon Cheney

Master's Theses

The CubeSat community has begun to develop and implement propulsion systems. This movement represents a new capability which may satisfy mission needs such as orbital and constellation maintenance, formation flight, de-orbit, and even interplanetary travel. With the freedom and capability granted by propulsion systems, CubeSat providers must accept new responsibilities in proportion to the potential hazards that propulsion systems may present.

The Cal Poly CubeSat program publishes and maintains the CubeSat Design Specification (CDS). They wish to help the CubeSat community to safety and responsibly expand its capabilities to include propulsive designs. For this reason, the author embarked on the …

Frequency-Limited Adaptive Control Of A Generic Transport Model In The Presence Of System Uncertainty And Losses In Control Effectiveness, Gerardo De La Torre, Tansel Yucelen, Wassim M. Haddad, Eric N. Johnson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

While adaptive control has been used in numerous applications to achieve system performance without excessive reliance on dynamical system models, the necessity of high-gain learning rates for safety-critical systems to achieve fast adaptation can be a serious limitation of most adaptive controllers. In order to address this problem, two novel adaptive control approaches developed recently aim to limit the bandwidth of the closed-loop adaptive control system in order to suppress the high-frequency content contained in the system error dynamics and adaptation algorithms. Specifically, this key feature of these frameworks allows for robust and fast adaptation by utilizing high-gain learning rates …

Preparation Of High Performance Porous Silicon Powders By Etching Al-Si Alloy In Acid Solution For Lithium Ion Battery, Shi-Ji Hao, Chun-Li Li, Kai Zhu, Ping Zhang, Zhi-Yu Jiang

Journal of Electrochemistry

Porous silicon powders prepared by etching Al-Si alloy using an acid solution was reported in the first time. The morphology and structure of as-obtained material were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD) method. It was found that the spongy porous silicon powders presented well crystalline structure and consisted of nano-Si particles. The particle size of porous Si powders was about 20 μm, and the specific surface area was 102.7 m²·g^-1. The electrochemical properties of porous silicon powders were evaluated as an anode material for lithium ion batteries. The material proportion in the …

Pulse Electrodeposition Of Pd-Ni Alloy Nanoparticles For Electrocatalytic Oxidation Of Formic Acid, Fang-Zu Yang, Jun-Pei Yue, Zhong-Qun Tian, Shao-Min Zhou

Journal of Electrochemistry

The Pd-Ni alloy nanoparticles with nickel atomic contents of 12.0%, 16.4% and 22.6% were successfully electrodeposited from a Pd-Ni alloy electrolyte by square wave pulse plating. The alloy nanoparticles were in the spherical shape with a diameter of 50 ~ 80 nm. As the growth potential of the alloy was negatively shifted, the nickel content of the alloy was increased, and the size of the nanoparticles was almost the same, whereas the number, the degree of crosslinking and the real active area of the nanoparticles were increased. As the nickel content of the alloy nanoparticles increased, the peak current for …

Underpotential Deposition Of Germanium On Au(111) And Pt(111) Surfaces In Ionic Liquids, Xu-Fen Xie, Jia-Wei Yan, Jing-Hong Liang, Ji-Jun Li, Meng Zhang, Bing-Wei Mao

Journal of Electrochemistry

The underpotential deposition (UPD) of germanium (Ge) in BMIPF₆ ionic liquids on Au(111) and Pt(111) surfaces have been investigated by cyclic voltammetry (CV) and in-situ scannin tunneling microscopy (STM). The CV results show that there are two reduction peaks related to the electrodeposition of Ge. The first reduction peak appeared in the CV curve may cover the transformation of Ge⁴⁺ to Ge²⁺ and the UPD of Ge. The second reduction peak corresponds to the bulk deposition of Ge. In-situ STM study suggests that the two UPD layers of Ge are formed on Au(111) and Pt(111) surfaces. The …

Synthesis And Electrochemical Properties Of Lico1-XMgXMno4 And Lico1-XAlXMno4 (X= 0, 0.02, 0.05, 0.1) As Positive Materials For Lithium-Ion Batteries, Mei-Ling You, Qing-Song Tong, Xiu-Hua Li, Min Lin, Xing-Kang Huang, Yong Yang

Journal of Electrochemistry

The Al-doped and Mg-doped LiCoMnO₄ materials were synthesized through solid-state reaction. The effects of doping amounts of Mg and Al on the initial capacities, discharge plateaus, and cycle performances were investigated. The morphologies and structures of the as-prepared materials were studied by scanning electron microscopy and powder X-ray diffraction. The results indicate that the as-prepared samples were composed of uniform, well-crystallized particles. The pristine LiCoMnO₄ possessed an initial capacity of 87.0 mAh·g^-1, while LiCo_0.98Mg_0.02MnO₄ and LiCo_0.98Al_0.02MnO₄ delivered 91.3 and 93.6 mAh·g^-1, respectively. The proper …

Passivation Behavior Of Aluminum Alloy During Electrochemical Machining And Its Effects On The Machining Performance, Li-Min Jiang, Wen-Bo Deng, Jun-Long Ying

Journal of Electrochemistry

The passivation behavior of aluminum alloy during electrochemical machining was investigated and discussed. The effects of processing voltage, current density, space of electrodes and electrolyte composition on electrochemical machining performance were explored. The results indicate that the electrochemical machining aluminum alloy in the composite electrolyte system containing NaNO₃ and NaF existed passivation phenomenon. Passivation action decreaseed the current efficiency and made it varied greatly with the current density. Also the passivation shifted the interspace characteristic curve of electrode notably to a negative direction. There was not passivation phenomenon in the composite electrolyte system containing the same concentrations of NaCl …

Fabrication And Impedance Performance Of Gradient Lani0.6Fe0.4O3-δ-Gd0.2Ce0.8O2 Composite Cathodes For Intermediate Temperature Solid Oxide Fuel Cell, Yang Li, Bo Huang, Meng Yuan, Zhi-Qiu Zhang, Zong-Yao Liu, Xu-Chen Tang, Xin-Jian Zhu

Journal of Electrochemistry

A LNF-GDC composite cathode with a gradual change in the composition between ScSZ electrolyte and LNF cathode was fabricated to reduce the cathode polarization resistance (R_p). The gradual change in composition between ScSZ electrolyte and LNF cathode shows the decreases in the charge transfer resistance (R_ct) and gas phase diffusion resistance (R_d). The results revealed that the Rp value, measuring 0.452 Ω·cm² at 750 °C, was the lowest for LNF-GDC composite cathodes with three layers and gradient changes in composition between ScSZ and LNF (Cathode C),, whereas the Rp value of 70%LNF-30%GDC composite …

Surface Structure And Electrochemical Performance Of Zno Coated Lini1/3Co1/3Mn1/3O2, Chang-Wei Liu, Yu Wang, Yu-Zhong Guo, Lu-Lu Dan, Jian-Hua Wang

Journal of Electrochemistry

The surface of LiNi_1/3Co_1/3Mn_1/3O₂ particles were modified by ZnO. Surface structure and electrochemical properties of the coated materials were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical tests. The results show that a ZnO coating affects the surface composition of LiNi_1/3Co_1/3Mn_1/3O₂ particles. The surface contents of nickel and manganese increase with the amount of ZnO coating. ZnO can react with LiNi_1/3Co_1/3Mn_1/3O₂ and a complex oxide is formed during the heat-treatment at above 400 ^oC. The …

Preliminary Study On Morphology Controllability Of Electrochemically Prepared Polyaniline By Using Aniline Aimer, Yang Zuo, Kang Shi

Journal of Electrochemistry

Employing of aniline dimer (N-phenyl-p-phenylenediamine, NPD) as the starting monomer, polyaniline was electrochemically synthesized on the surface of glassy carbon electrode in acetonitrile-aqueous mixing solutions（20% by volume）containing 1 mol·L^-1 HClO₄. Experimental results demonstrated that the polymerization of NPD occurs at the potentials about 0.2 V lower than those of aniline monomer. Furthermore, the resulting polyaniline has higher morphology controllability than those synthesized by using aniline as the stating monomer. The uniform polyaniline nanoparticles (30 nm in diameter), ultralong nanowires (length > 5 μm, 50 nm in diameter) or large area nanosheets (4 μm in length, 2 μm in …

Electrochemical Oxidation Of Ammonium Nitrite In Absorption Solution Of Flue Gas, Yong-Hong Lu, Xiao-Bo Dong, Li-Sha Wang, Yan Liu, Chen-Jian Zhu, Hai-Bo Xu

Journal of Electrochemistry

In order to make full uses of ammonium nitrite in absorption solution from flue gas simultaneous desulfurization, denitrification and demercurization processes, here the electrochemical oxidation method was used to transform ammonium nitrite into ammonium nitrate. By using polarization curve, cyclic voltammogram and galvanostatic methods, suitable electrode materials were evaluated and chosen. The influence of electrolyte composition was discussed and the appropriate process parameters were obtained. Finally, the effect of electrochemical oxidation was confirmed by chemical analysis method. In 0.05 mol·L^-1 NaNO₂ + 0.05 mol·L^-1 (NH₄)₂SO₄ simulated absorption solution (5 L, pH = …

Study On Carbon Supported Pd Catalysts Modified By Phosphomolybdic Acid For H2O2 Electrocatalytic Reduction, Li-Mei Sun, Cheng Zhang, Ying-Rong Bao, Hong-Xia Li

Journal of Electrochemistry

The Pd/C catalyst was prepared with the chemical reduction method, and phosphomolybdic acid (PMA) was modified on the Pd/C catalyst using the dipping method. The compositions and structures of the Pd/C and Pd/C modified by phosphomolybdic acid (PMA-Pd/C) catalysts were characterized with X-ray diffraction and Fourier Transform infrared spectroscopy analyses. The electrocatalytic activity and stability of the catalysts for the reduction of hydrogen peroxide (H₂O₂) were studied using cyclic voltammetry and chronoamperometry. The results showed that the phosphomolybdic acid was tightly fixed on the surface of Pd/C catalyst through the chemical interaction. The eletrocatalytic activity of …

Preparation Of Pd/Tio2/C Catalyst And Its Electrocatalytic Performance In Basic Solution For Ethanol Oxidation, Qiao-Xia Li, Yi-Chao Yang, Ming-Shuang Liu, Hong-Min Mao, Qun-Jie Xu

Journal of Electrochemistry

Nanoparticles TiO₂ were prepared by hydrothermal method using precursor tetrabutyl titanate. The Pd/TiO₂/C catalyst was synthesized by liquid phase reducing method supported on nano TiO₂ and Vulcan carbon XC-72. The Pd/TiO₂/C catalyst was characterized by XRD, TEM, cyclic voltammetry, and chronopotentiometry. XRD confirmed the face-centered cubic structure of Pd particles, and TEM indicated that Pd particles (size 3 ~ 4 nm) dispersed uniformly on TiO₂ and carbon XC-72. The results from cyclic voltammogram and chronopotentiogram showed the higher ethanol oxidation activity and stability of Pd/TiO₂/C catalyst (20% Pd) as compared with …

Design And Development Of A Novel Glucose Biosensor Based On The Ferrocene-Functionalized Fe3O4 Nanoparticles/Carbon Nanotubes/Chitosan Nanocomposite Film Modified Electrode, Hua-Ping Peng, Dai-Jun Zha, Wei Chen, Ai-Lin Liu, Xin-Hua Lin

Journal of Electrochemistry

A novel platform for the fabrication of glucose biosensor was successfully constructed by entrapping glucose oxidase (GOD) in a ferrocene monocarboxylic acid-aminated Fe₃O₄ magnetic nanoparticles conjugate (FMC-AFNPs)/chitosan (CS)/multiwall carbon nanotubes (MWNTs) nanocomposite. The formation of FMC-AFNPs could effectively prevent the leakage of ferrocene and retain its electrochemical activity. This GOD/FMC-AFNPs/CS/MWNTs matrix provided a biocompatible microenvironment for retaining the native activity of the immobilized GOD. Moreover, the presence of MWNTs enhanced the charge-transport properties of the composite and facilitated electron transfer between the GOD and the electrode for the electrocatalysis of glucose. Under the optimal conditions the designed …

A New Nonenzymatic Glucose Sensor Based On The Cuo Nanoplatelets, Yan-Cai Li, Fu-Ying Huang, Shun-Xing Li, Jie Chen, Shu-Qing Feng, Fei Wang

Journal of Electrochemistry

The CuO nanoplatelets were synthesized by hydrothermal method. The structure and morphology of the CuO nanoplatelets were characterized by TEM and XRD. A new nonenzymatic glucose sensor was constructed by immobilizing the CuO nanoplatelets on glassy carbon electrode with Nafion. The electrochemical performance of the CuO/Nafion/GCE for the detection of glucose was investigated by cyclic voltammetry and current-time curve. The experiment results showed that the linear dependence of the sensor was 0.01 to 0.3 mmol·L^-1 for glucose with a sensitivity of 1783.58 μA·mmol^-1·L·cm^-2, and the detection limit of the sensor was 0.80 μmol·L^-1 (S/N …

The Santa Clara, 2014-02-27, Santa Clara University

The Santa Clara

No abstract provided.

Agenda: Natural Resource Industries And The Sustainability Challenge, University Of Colorado Boulder. Getches-Wilkinson Center For Natural Resources, Energy, And The Environment, University Of Colorado Boulder. The Colorado Law Energy Innovation Initiative

Natural Resource Industries and the Sustainability Challenge (Martz Winter Symposium, February 27-28)

"An International Conference hosted by The Getches-Wilkinson Center for Natural Resources, Energy, and the Environment and The Colorado Law Energy Innovation Initiative."

For more than two decades, sustainability has gained currency as a broad organizing principle for efforts to develop and use energy, natural resources, and the environment in ways that allow society to meet its needs without compromising the ability of future generations to meet their needs. More recently, sustainability has been embraced by businesses across multiple sectors as part of a broader movement of corporate social responsibility. Hardly a day goes by without news of another corporate initiative …

Slides: Comments Of Jeff Bingaman, Jeff Bingaman

Natural Resource Industries and the Sustainability Challenge (Martz Winter Symposium, February 27-28)

Presenter: Jeff Bingaman, former Chair of the Senate Energy and Natural Resources Committee and U.S. Senator from New Mexico

6 slides

Methods, Systems, And Devices For Surgical Access And Inserton, Tom Frederick, Shane Farritor, Jack Mondry, Eric Markvicka, Dmitry Oleynikov, Jacob Greenburg

Department of Mechanical and Materials Engineering: Faculty Publications

The various embodiments herein relate to systems, devices, and/or methods relating to Surgical procedures, and more specifically for accessing an insufflated cavity of a patient and/or positioning Surgical systems or devices into the cavity.