Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Chemical Engineering (21)
- Materials Science and Engineering (14)
- Bioresource and Agricultural Engineering (12)
- Life Sciences (12)
- Mechanical Engineering (11)
-
- Agriculture (10)
- Other Materials Science and Engineering (10)
- Nanoscience and Nanotechnology (9)
- Physical Sciences and Mathematics (9)
- Ceramic Materials (8)
- Biochemical and Biomolecular Engineering (7)
- Operations Research, Systems Engineering and Industrial Engineering (7)
- Animal Sciences (6)
- Aquaculture and Fisheries (6)
- Biological Engineering (5)
- Biomedical Engineering and Bioengineering (5)
- Chemistry (5)
- Civil and Environmental Engineering (5)
- Complex Fluids (5)
- Electrical and Computer Engineering (5)
- Energy Systems (5)
- Public Affairs, Public Policy and Public Administration (5)
- Social and Behavioral Sciences (5)
- Structural Engineering (5)
- Aerospace Engineering (4)
- Other Chemical Engineering (4)
- Systems Engineering and Multidisciplinary Design Optimization (4)
- Aerodynamics and Fluid Mechanics (3)
- Applied Mechanics (3)
- Keyword
-
- Aquaculture Feeds (4)
- Crystal structure (4)
- DDGS (4)
- NURBS (4)
- Aquaculture (3)
-
- Department of Agricultural and Biological Engineering (3)
- Fluid-structure interaction (3)
- Geological and Atmospheric Sciences (3)
- Weldon School of Biomedical Engineering (3)
- Aerodynamic torque (2)
- Biosensing (2)
- Birck Nanotechnology Center and Bindley Bioscience Center (2)
- Foreign body response (2)
- Isogeometric analysis (2)
- Modeling (2)
- Nanotechnology (2)
- Physical Properties (2)
- Protein (2)
- Wind turbine rotor (2)
- Adaptive Human-Machine Interface (1)
- Adaptive systems (1)
- Adenosine triphosphate (1)
- Air traffices (1)
- Air-water interfaces (1)
- Alternative Energy Sources (1)
- Amaranth (1)
- Amperometric (1)
- Amphiphilics (1)
- Analytical solution of non-linear differential equation (1)
- Anodic alumina template (1)
- Publication
-
- Kurt A. Rosentrater (12)
- Anja V. Mudring (10)
- Ming-Chen Hsu (5)
- Simon Laflamme (5)
- Kaitlin M. Bratlie (4)
-
- Michael C. Dorneich (4)
- Ganesh Balasubramanian (3)
- Jonathan C. Claussen (3)
- R. Dennis Vigil (3)
- Sarah A. Rajala (2)
- Sarah M. Ryan (2)
- Wenyu Huang (2)
- Brett VanVeller (1)
- Daniel Attinger (1)
- David C. Jiles (1)
- John R. Bowler (1)
- Kris De Brabanter (1)
- Martin M. Thuo (1)
- Mingyi Hong (1)
- Zengyi Shao (1)
Articles 31 - 60 of 63
Full-Text Articles in Engineering
Wavelet Network For Semi-Active Control, Simon Laflamme, J.J.E. Slotine, J.J. Connor
Wavelet Network For Semi-Active Control, Simon Laflamme, J.J.E. Slotine, J.J. Connor
Simon Laflamme
This paper proposes a wavelet neurocontroller capable of self-adaptation and self-organization for uncertain systems controlled with semi-active devices, ideal candidates for control of large-scale civil structures. A condition on the sliding surface for cantilever-like structures is defined. The issue of applicability of the control solution to largescale civil structures is made the central theme throughout the text, as this topic has not been extensively discussed in the literature. Stability and convergence of the proposed neurocontroller is assessed through various numerical simulations for harmonic, earthquake, and wind excitations. The simulations consist of semi-active dampers installed as a replacement to the current …
Experimental And Molecular Dynamics Investigation Into The Amphiphilic Nature Of Sulforhodamine B, Baris E. Polat, Shangchao Lin, Jonathan D. Mendenhall, Brett Vanveller, Robert Langer, Daniel Blankschtein
Experimental And Molecular Dynamics Investigation Into The Amphiphilic Nature Of Sulforhodamine B, Baris E. Polat, Shangchao Lin, Jonathan D. Mendenhall, Brett Vanveller, Robert Langer, Daniel Blankschtein
Brett VanVeller
Sulforhodamine B (SRB), a common fluorescent dye, is often considered to be a purely hydrophilic molecule, having no impact on bulk or interfacial properties of aqueous solutions. This assumption is due to the high water solubility of SRB relative to most fluorescent probes. However, in the present study, we demonstrate that SRB is in fact an amphiphile, with the ability to adsorb at an air/water interface and to incorporate into sodium dodecyl sulfate (SDS) micelles. In fact, SRB reduces the surface tension of water by up to 23 mN/m, and the addition of SRB to an aqueous SDS solution induces …
Kernel Regression In The Presence Of Correlated Errors, Kris De Brabanter, Jos De Brabanter, Johan A.K. Suykens, Bart De Moor
Kernel Regression In The Presence Of Correlated Errors, Kris De Brabanter, Jos De Brabanter, Johan A.K. Suykens, Bart De Moor
Kris De Brabanter
It is a well-known problem that obtaining a correct bandwidth and/or smoothing parameter in nonparametric regression is difficult in the presence of correlated errors. There exist a wide variety of methods coping with this problem, but they all critically depend on a tuning procedure which requires accurate information about the correlation structure. We propose a bandwidth selection procedure based on bimodal kernels which successfully removes the correlation without requiring any prior knowledge about its structure and its parameters. Further, we show that the form of the kernel is very important when errors are correlated which is in contrast to the …
Microbiosensors Based On Dna Modified Single-Walled Carbon Nanotube And Pt Black Nanocomposites, Jin Shi, Tae-Gon Cha, Jonathan C. Claussen, Alfred R. Diggs, Jong Hyun Choi, D. Marshall Porterfield
Microbiosensors Based On Dna Modified Single-Walled Carbon Nanotube And Pt Black Nanocomposites, Jin Shi, Tae-Gon Cha, Jonathan C. Claussen, Alfred R. Diggs, Jong Hyun Choi, D. Marshall Porterfield
Jonathan C. Claussen
Glucose and ATP biosensors have important applications in diagnostics and research. Biosensors based on conventional materials suffer from low sensitivity and low spatial resolution. Our previous work has shown that combining single-walled carbon nanotubes (SWCNTs) with Pt nanoparticles can significantly enhance the performance of electrochemical biosensors. The immobilization of SWCNTs on biosensors remains challenging due to the aqueous insolubility originating from van der Waals forces. In this study, we used single-stranded DNA (ssDNA) to modify SWCNTs to increase solubility in water. This allowed us to explore new schemes of combining ssDNA-SWCNT and Pt black in aqueous media systems. The result …
Electrochemical Glutamate Biosensing With Nanocube And Nanosphere Augmented Single-Walled Carbon Nanotube Networks: A Comparative Study, Jonathan C. Claussen, Mayra S. Artiles, Eric S. Mclamore, Subhashree Mohanty, Jin Shi, Jenna L. Rickus, Timothy S. Fisher, D. Marshall Porterfield
Electrochemical Glutamate Biosensing With Nanocube And Nanosphere Augmented Single-Walled Carbon Nanotube Networks: A Comparative Study, Jonathan C. Claussen, Mayra S. Artiles, Eric S. Mclamore, Subhashree Mohanty, Jin Shi, Jenna L. Rickus, Timothy S. Fisher, D. Marshall Porterfield
Jonathan C. Claussen
We describe two hybrid nanomaterial biosensor platforms, based on networks of single-walled carbon nanotubes (SWCNTs) enhanced with Pd nanocubes and Pt nanospheres and grown in situ from a porous anodic alumina (PAA) template. These nanocube and nanosphere SWCNT networks are converted into glutamate biosensors by immobilizing the enzyme glutamate oxidase (cross-linked with gluteraldehyde) onto the electrode surface. The Pt nanosphere/SWCNT biosensor outperformed the Pd nanocube/SWCNT biosensor and previously reported similar nanomaterial-based biosensors by amperometrically monitoring glutamate concentrations with a wide linear sensing range (50 nM to 1.6 mM) and a small detection limit (4.6 nM, 3s). These results combined with …
3d Simulation Of Wind Turbine Rotors At Full Scale. Part I: Geometry Modeling And Aerodynamics, Y. Bazilevs, Ming-Chen Hsu, I. Akkerman, S. Wright, K. Takizawa, B. Henicke, T. Spielman, T. E. Tezduyar
3d Simulation Of Wind Turbine Rotors At Full Scale. Part I: Geometry Modeling And Aerodynamics, Y. Bazilevs, Ming-Chen Hsu, I. Akkerman, S. Wright, K. Takizawa, B. Henicke, T. Spielman, T. E. Tezduyar
Ming-Chen Hsu
In this two-part paper we present a collection of numerical methods combined into a single framework, which has the potential for a successful application to wind turbine rotor modeling and simulation. In Part 1 of this paper we focus on: 1. The basics of geometry modeling and analysis-suitable geometry construction for wind turbine rotors; 2. The fluid mechanics formulation and its suitability and accuracy for rotating turbulent flows; 3. The coupling of air flow and a rotating rigid body. In Part 2 we focus on the structural discretization for wind turbine blades and the details of the fluid–structure interaction computational …
Nanotechnology Education—First Step In Implementing A Spiral Curriculum, Ganesh Balasubramanian, Vinod K. Lohani, Ishwar K. Puri, Scott W. Case, Roop L. Mahajan
Nanotechnology Education—First Step In Implementing A Spiral Curriculum, Ganesh Balasubramanian, Vinod K. Lohani, Ishwar K. Puri, Scott W. Case, Roop L. Mahajan
Ganesh Balasubramanian
A nanotechnology learning module was implemented into a freshman engineering course at Virginia Tech. The novelty of our approach is that an established spiral curriculum model has been employed, for the first time to the best of authors’ knowledge, to design the nanotechnology option. The module was piloted in a freshman class (180 students) during spring ‘08. The key components included (1) a prior knowledge survey, (2) a 40-minute in-class presentation on basic nanotechnology concepts, (3) an activity that involves nanoscale image analysis and the plotting of molecular forces usingLabVIEWsoftware,and(4)apost-modulesurvey.Lessonslearnedfromthepilotimplementationwereincorporated appropriately to expose roughly 1450 freshmen to nanotechnology basics in …
Effects Of Carbon Nanotube-Tethered Nanosphere Density On Amperometric Biosensing: Simulation And Experiment, Jonathan C. Claussen, James B. Hengenius, Monique M. Wickner, Timothy S. Fisher, David M. Umulis, D. Marshall Porterfield
Effects Of Carbon Nanotube-Tethered Nanosphere Density On Amperometric Biosensing: Simulation And Experiment, Jonathan C. Claussen, James B. Hengenius, Monique M. Wickner, Timothy S. Fisher, David M. Umulis, D. Marshall Porterfield
Jonathan C. Claussen
Nascent nanofabrication approaches are being applied to reduce electrode feature dimensions from the microscale to the nanoscale, creating biosensors that are capable of working more efficiently at the biomolecular level. The development of nanoscale biosensors has been driven largely by experimental empiricism to date. Consequently, the precise positioning of nanoscale electrode elements is typically neglected, and its impact on biosensor performance is subsequently overlooked. Herein, we present a bottom-up nanoelectrode array fabrication approach that utilizes low-density and horizontally oriented single-walled carbon nanotubes (SWCNTs) as a template for the growth and precise positioning of Pt nanospheres. We further develop a computational …
Ionic Liquids As Crystallization Media: Weakly-Coordinating Anions Do Coordinate In 1∞[Eu(Otf)3(Ch3cn)3], Sifu Tang, Anja V. Mudring
Ionic Liquids As Crystallization Media: Weakly-Coordinating Anions Do Coordinate In 1∞[Eu(Otf)3(Ch3cn)3], Sifu Tang, Anja V. Mudring
Anja V. Mudring
Tris(acetonitrile)tris(trifluoromethanesulfonato)-europium(III), 1∞[Eu(OTf)3(CH3CN)3], is the first structurally characterized Ln(OTf)3-solvate where triflate is still in the coordination sphere of the Ln(III) cation and not substituted by solvate molecules. This fact is attributed to the unique crystallization conditions that an ionic liquid provides: 1∞[Eu(OTf)3(CH3CN)3] was obtained from a solution of europium(III) triflate, Eu(OTf)3, with acetonitrile in the ionic liquid [C4py][OTf] (1-butylpyridinium triflate). The crystal structure (triclinic, P1̅ (no. 2), a = 5.734(1) Å, b = 10.500(2) Å, c = 19.088(4) Å, α = 98.09(3)°, β = 93.79(3)°, γ = 91.46(3)°, V = 1134.5(4) Å3, Z = 2, R1 for 4388 reflections with Io …
Spatiotemporal Effects Of A Controlled-Release Anti-Inflammatory Drug On The Cellular Dynamics Of Host Response, Tram T. Dang, Kaitlin M. Bratlie, Said R. Bogatyrev, Xiao Chen, Robert Langer, Daniel G. Anderson
Spatiotemporal Effects Of A Controlled-Release Anti-Inflammatory Drug On The Cellular Dynamics Of Host Response, Tram T. Dang, Kaitlin M. Bratlie, Said R. Bogatyrev, Xiao Chen, Robert Langer, Daniel G. Anderson
Kaitlin M. Bratlie
In general, biomaterials induce a non-specific host response when implanted in the body. This reaction has the potential to interfere with the function of the implanted materials. One method for controlling the host response is through local, controlled-release of anti-inflammatory agents. Herein, we investigate the spatial and temporal effects of an anti-inflammatory drug on the cellular dynamics of the innate immune response to subcutaneously implanted poly(lactic-co-glycolic) microparticles. Noninvasive fluorescence imaging was used to investigate the influence of dexamethasone drug loading and release kinetics on the local and systemic inhibition of inflammatory cellular activities. Temporal monitoring of host response showed that …
The Crew Workload Manager: An Open-Loop Adaptive System Design For Next Generation Flight Decks, Michael C. Dorneich, Bretislav Passinger, Christopher Hamblin, Claudia Keinrath, Jiri Vasek, Stephen D. Whitlow, Martijin Beekhuyzen
The Crew Workload Manager: An Open-Loop Adaptive System Design For Next Generation Flight Decks, Michael C. Dorneich, Bretislav Passinger, Christopher Hamblin, Claudia Keinrath, Jiri Vasek, Stephen D. Whitlow, Martijin Beekhuyzen
Michael C. Dorneich
This paper presents an open loop adaptive system intended to address workload imbalances in future, high-workload flight decks. Air traffic in Europe is expected to more than double by 2020. New technologies being proposed will significantly add to pilot roles and responsibilities, and has the potential to add further periods of high workload to pilot operations. The CAMMI (Cognitive Adaptive Man Machine Interface) program addresses human factors priorities in the aviation domain by developing concepts that balance operator workload, support added future operator roles and responsibilities and resulting new task and information requirements, while allowing operators to focus on the …
Rapid Characterization And Engineering Of Natural Product Biosynthetic Pathways Via Dna Assembler, Zengyi Shao, Yunzi Luo, Huimin Zhao
Rapid Characterization And Engineering Of Natural Product Biosynthetic Pathways Via Dna Assembler, Zengyi Shao, Yunzi Luo, Huimin Zhao
Zengyi Shao
We report a synthetic biology strategy for rapid genetic manipulation of natural product biosynthetic pathways. Based on DNA assembler, this method synthesizes the entire expression vector containing the target biosynthetic pathway and the genetic elements required for DNA maintenance and replication in various hosts in a single-step manner through yeast homologous recombination, offering unprecedented flexibility and versatility in pathway manipulations.
Understanding Student Pathways In Context-Rich Problems, Pavlo Antonenko, John Jackman, Piyamart Kumsaikaew, Rahul Marathe, Dale Niederhauser, Craig Ogilvie, Sarah Ryan
Understanding Student Pathways In Context-Rich Problems, Pavlo Antonenko, John Jackman, Piyamart Kumsaikaew, Rahul Marathe, Dale Niederhauser, Craig Ogilvie, Sarah Ryan
Sarah M. Ryan
In this paper we investigate the ways that students' problem-solving behaviors evolve when solving multi-faceted, context-rich problems within a structured, computer-based learning environment. During the semester, groups of two or three students worked on several problems that required drawing on more than one concept and, hence, could not be readily solved with simple "plug-and-chug" strategies. The problems were presented to students in a data-rich, online problem-solving environment that tracked which information items were selected by students as they attempted to solve the problem. The students also completed a variety of tasks, like entering an initial qualitative analysis into an online …
Strongly Enhanced Sensitivity In Elastic Capacitive Strain Sensors, Matthias Kollosche, Hristiyan Stoyanov, Simon Laflamme, Guggi Kofod
Strongly Enhanced Sensitivity In Elastic Capacitive Strain Sensors, Matthias Kollosche, Hristiyan Stoyanov, Simon Laflamme, Guggi Kofod
Simon Laflamme
Strain sensors based on dielectric elastomer capacitors function by the direct coupling of mechanical deformations with the capacitance. The coupling can be improved by enhancing the relative permittivity of the dielectric elastomer. Here, this is carried out through the grafting of conducting polymer (poly-aniline) to the elastomer backbone, leading to molecular composites. An enhancement in capacitance response of 46 times is observed. This could help to extend the possible range of miniaturization towards even smaller device features.
Rh1−Xpdxnanoparticle Composition Dependence In Co Oxidation By Oxygen: Catalytic Activity Enhancement In Bimetallic Systems, James Russell Renzas, Wenyu Huang, Yawen Zhang, Michael E. Grass, Dat Tien Hoang, Selim Alayoglu, Derek R. Butcher, Franklin Tao, Zhi Liu, Gabor A. Somorjai
Rh1−Xpdxnanoparticle Composition Dependence In Co Oxidation By Oxygen: Catalytic Activity Enhancement In Bimetallic Systems, James Russell Renzas, Wenyu Huang, Yawen Zhang, Michael E. Grass, Dat Tien Hoang, Selim Alayoglu, Derek R. Butcher, Franklin Tao, Zhi Liu, Gabor A. Somorjai
Wenyu Huang
Bimetallic 15 nm Rh1−xPdxnanoparticle catalysts of five different compositions and supported on Si wafers have been synthesized, characterized using TEM, SEM, and XPS, and studied in CO oxidation by O2 in two pressure regimes: atmospheric pressure and 100–200 mTorr. The RhPd bimetallic nanocrystals exhibited similar synergetic effect of increased reaction activity at both atmospheric (760 Torr) and moderate (100–200 mTorr) pressures compared with pure Pd or Rh. The magnitude of the effect depends on the relative pressures of the CO and O2 reactant gases and the reaction temperature. The catalytic activity of the nanocrystals measured at moderate pressure is directly …
Integrated Data Link Concept - An Adaptive System Facilitating Controller Pilot Data Link Communication, Michael C. Dorneich, Jiri Vasek, Claudia Keinrath, Petr Krupansky, Bretislav Passinger, Stephen Whitlow, Chris Hamblin
Integrated Data Link Concept - An Adaptive System Facilitating Controller Pilot Data Link Communication, Michael C. Dorneich, Jiri Vasek, Claudia Keinrath, Petr Krupansky, Bretislav Passinger, Stephen Whitlow, Chris Hamblin
Michael C. Dorneich
An adaptive system to address workload issues due to the migration towards datalink communications in future flight decks is presented in this paper. Air traffic in Europe is expected to more than double by 2020. New technologies being proposed will significantly add to pilot roles and responsibilities, and has the potential to add further periods of high workload to pilot operations. The CAMMI (Cognitive Adaptive Man Machine Interface) program addresses human factors priorities in the aviation domain by developing concepts that balance operator workload, support added future operator roles and responsibilities and resulting new task and information requirements, while allowing …
Efficient Quantum Cutting In Hexagonal Nagdf4:Eu3+ Nanorods, Pushpal Ghosh, Sifu Tang, Anja V. Mudring
Efficient Quantum Cutting In Hexagonal Nagdf4:Eu3+ Nanorods, Pushpal Ghosh, Sifu Tang, Anja V. Mudring
Anja V. Mudring
An ionic liquid (IL) assisted solvothermal method is employed to prepare single phase, oxygen free, hexagonal NaGdF4:Eu3+ (2 mol%) nanorods with a visible quantum efficiency of 187%. In contrast, for mixed materials containing cubic and hexagonal NaGdF4:Eu3+, the quantum efficiency is much less (127%). Thus, synthesis parameters have to be carefully chosen in order to get the high performance hexagonal material. Not only the influence of the IL but also of the Gd : F ratio during synthesis as well as the temperature were studied. It is found that the IL stabilizes the formation of hexagonal NaGdF4:Eu3+, likewise a fluoride …
Stability And Growth Behavior Of Transition Metal Nanoparticles In Ionic Liquids Prepared By Thermal Evaporation: How Stable Are They Really?, Kai Richter, Alexander Birkner, Anja V. Mudring
Stability And Growth Behavior Of Transition Metal Nanoparticles In Ionic Liquids Prepared By Thermal Evaporation: How Stable Are They Really?, Kai Richter, Alexander Birkner, Anja V. Mudring
Anja V. Mudring
Recently we developed an access to metal- and metal-oxide colloids based on thermal evaporation of metals into ionic liquids (ILs). Here we present systematic studies on the long-time stability of gold and copper nanoparticles (NPs) in different ILs. The influence of metal concentration and temperature on the ripening of the as-prepared gold NPs in different ILs was investigated by transmission electron microscopy (TEM) and UV-vis absorption measurements. Short alkyl chain-length-methyl-imidazolium salts with weakly coordinating perfluorinated counter anions (PF6, BF4 or Tf2N, bis(trifluoromethanesulfonyl)amide) were found to be better stabilizers compared to ILs with cations bearing long alkyl chains (trihexyltetradecylphosphonium, 1-octyl-3-methylimidazolium) and …
Structures, Electronic Properties And Solid State Luminescence Of Cu(I) Iodide Complexes With 2,9-Dimethyl-1,10-Phenanthroline And Aliphatic Aminomethylphosphines Or Triphenylphosphine, Radoslaw Starosta, Malgorzata Puchalska, Joanna Cybinska, Maciej Barys, Anja V. Mudring
Structures, Electronic Properties And Solid State Luminescence Of Cu(I) Iodide Complexes With 2,9-Dimethyl-1,10-Phenanthroline And Aliphatic Aminomethylphosphines Or Triphenylphosphine, Radoslaw Starosta, Malgorzata Puchalska, Joanna Cybinska, Maciej Barys, Anja V. Mudring
Anja V. Mudring
The luminescent complexes of triphenylphosphine and two interesting aminomethylphosphines: P(CH2N(CH2CH2)2NCH3)3 and P(CH2N(CH2CH2)2O)3 with copper(I) iodide and 2,9-dimethyl-1,10-phenanthroline (dmp): [CuI(dmp)PPh3], [CuI(dmp)P(CH2N(CH2CH2)2NCH3)3] and [CuI(phen)P(CH2N(CH2CH2)2O)3] are presented in this work. These complexes were characterized in solution by means of NMR spectroscopy and their structures were crystallographically determined in the solid state. All complexes crystallize as the discrete dimers bound by π-stacking interactions between dmp rings. The coordination geometry about the Cu(I) centre is pseudo-tetrahedral showing small flattening and large rocking distortions. The investigated compounds exhibit intense orange photoluminescence in the solid state (emission peaks at r.t.: λmax = 588–592 nm; τ = 1.7–2.2 …
In-Situ Crystal Growth And Properties Of The Magnetic Ionic Liquid [C2mim][Fecl4], Tobias Backer, Oliver Breunig, Klaus Merz, Vera Vasylyeva, Anja V. Mudring
In-Situ Crystal Growth And Properties Of The Magnetic Ionic Liquid [C2mim][Fecl4], Tobias Backer, Oliver Breunig, Klaus Merz, Vera Vasylyeva, Anja V. Mudring
Anja V. Mudring
[C2mim][FeCl4] behaves like a paramagnetic liquid at room temperature. Specific heat measurements indicate that there is a magnetic ordering below 3.8 K. The released entropy is far from the expected value for a J = 5/2 system, implying that the magnetic state is partly disordered. Full magnetic polarization was reached in fields above 4 T, and the anomaly in the magnetic susceptibility can be fully suppressed in higher B fields. Hence, the suggested magnetic ground state is superparamagnetic. In order to better understand the magnetic nature of this compound, structural investigations were carried out. Raman and IR-spectroscopy as well as …
Long Term Resource Planning For Electric Power Systems Under Uncertainty, Sarah M. Ryan, James D. Mccalley, David L. Woodruff
Long Term Resource Planning For Electric Power Systems Under Uncertainty, Sarah M. Ryan, James D. Mccalley, David L. Woodruff
Sarah M. Ryan
Electric power systems are subject to uncertainties of many types and at many levels. In addition to the uncertain fuel prices, demand growth, and equipment outages included in traditional models, current trends portend increasing uncertainty due to such factors as the growth in generation from renewable sources which may be intermittent, the possibility of regulations to control carbon emissions, and the increasing price responsiveness of demand encouraged by smart grid technologies. This paper begins by discussing issues that confront electric system planners and explains the requirements for useful tools. We continue with a description of academic and commercial planning models …
Dead Zones In Porous Catalysts: Concentration Profiles And Efficiency Factors, Roger L. York, Kaitlin M. Bratlie, Lloyd R. Hile, Larry K. Jang
Dead Zones In Porous Catalysts: Concentration Profiles And Efficiency Factors, Roger L. York, Kaitlin M. Bratlie, Lloyd R. Hile, Larry K. Jang
Kaitlin M. Bratlie
This paper examines the conditions under which a dead zone, or a portion of the catalyst devoid of reactant, can form in a porous catalyst in which simultaneous reaction and diffusion are occurring. The condition that allows for the existence of a dead zone is defined by a critical Thiele modulus. When the Thiele modulus - the ratio of chemical reaction to diffusion - is greater than the critical Thiele modulus, a dead zone exists. This dead zone can be mathematically defined by a change of boundary conditions. We examine nth order reactions in isothermal infinite slabs, infinite cylinders, and …
Rh1−X Pd X Nanoparticle Composition Dependence In Co Oxidation By No, James Russell Renzas, Wenyu Huang, Yawen Zhang, Michael E. Grass, Gabor A. Somorjai
Rh1−X Pd X Nanoparticle Composition Dependence In Co Oxidation By No, James Russell Renzas, Wenyu Huang, Yawen Zhang, Michael E. Grass, Gabor A. Somorjai
Wenyu Huang
Bimetallic 15 nm Pd-core Rh-shell Rh1−x Pd x nanoparticle catalysts have been synthesized and studied in CO oxidation by NO. The catalysts exhibited composition-dependent activity enhancement (synergy) in CO oxidation in high NO pressures. The observed synergetic effect is attributed to the favorable adsorption of CO on Pd in NO-rich conditions. The Pd-rich bimetallic catalysts deactivated after many hours of oxidation of CO by NO. After catalyst deactivation, product formation was proportional to the Rh molar fraction within the bimetallic nanoparticles. The deactivated catalysts were regenerated by heating the sample in UHV. This regeneration suggests that the deactivation was caused …
Development Of Cationic Polymer Coatings To Regulate Foreign-Body Responses, Minglin Ma, Wendy F. Liu, Paulina S. Hill, Kaitlin M. Bratlie, Daniel J. Siegwart, Justin Chin, Miri Park, Joao Guerreiro, Daniel G. Anderson
Development Of Cationic Polymer Coatings To Regulate Foreign-Body Responses, Minglin Ma, Wendy F. Liu, Paulina S. Hill, Kaitlin M. Bratlie, Daniel J. Siegwart, Justin Chin, Miri Park, Joao Guerreiro, Daniel G. Anderson
Kaitlin M. Bratlie
A library of cationic polymers, poly(beta-amino alcohols) with a great chemical diversity are synthesized using combinatorial polymerization. These polymers, when immobilized on a surface, drastically affect the behavior of monocyte/macrophage cells in vitro and early inflammatory reactions in vivo. Certain polymers are found capable of mitigating the foreign-body responses.
Influence Of Reactive Atmosphere On Properties Of Cobalt Ferrite Thin Films Prepared Using Pulsed-Laser Deposition, A. Raghunathan, David C. Jiles, J. E. Snyder
Influence Of Reactive Atmosphere On Properties Of Cobalt Ferrite Thin Films Prepared Using Pulsed-Laser Deposition, A. Raghunathan, David C. Jiles, J. E. Snyder
David C. Jiles
A series of cobaltferrite (CFO) thin films were grown on SiO2/Si(100) substrates using pulsed-laser deposition (PLD) at substrate temperature (T DEP) of 250 °C and oxygen pressures (P O2) from 0.67 to 6.7 Pa. The influence of PO2 on crystal structure, phase mixture, deposition rate, and magnetic properties was investigated. It is shown in this study that there is a window of PO2 for optimized growth of nanograined CFO films at low T DEP and that either higher or lower values of PO2 produce undesirable multiphase mixtures. CFO filmsgrown at such low substrate temperature and optimized oxygen pressure on thermal …
A New Open-Framework Iron Borophosphate From Ionic Liquids: Kfe[Bp2o8(Oh)], Guangmei Wang, Anja V. Mudring
A New Open-Framework Iron Borophosphate From Ionic Liquids: Kfe[Bp2o8(Oh)], Guangmei Wang, Anja V. Mudring
Anja V. Mudring
A new open-framework iron borophosphate, KFe[BP2O8(OH)], has been obtained by ionothermal synthesis from KH2PO4, FeCl3∙4H2O, H3BO3 and [C4mpyr]Br (1-butyl-1-methylpyrrolidinium bromide). Single-crystal X-ray diffraction analysis shows that KFe[BP2O8(OH)] (monoclinic, P21/c, a = 9.372(2) Å , b = 8.146(2)Å , c = 9.587(2) Å, β = 101.18(3)°, V = 718.0(2)Å3 and Z = 4) has a three-dimensional (3-D) framework structure composed by {Fe(III)O5(OH)} octahedra as well as {BO3(OH)} and {PO4} tetrahedra. As anionic structural sub-unit, KFe[BP2O8(OH)], contains an infinite open-branched {[BP2O8(OH)]4-} chain which is formed by alternating {BO3(OH)} and {PO4} tetrahedra. {Fe(III)O5(OH)} octahedra share common O corners with five phosphate tetrahedra and …
The First Lanthanide Telluride-Bromide: La3te4br, A Valence Compound, Markus Larres, Anja V. Mudring, Gerd Meyer
The First Lanthanide Telluride-Bromide: La3te4br, A Valence Compound, Markus Larres, Anja V. Mudring, Gerd Meyer
Anja V. Mudring
The first ternary lanthanide telluride-bromide La3Te4Br was obtained from a mixture of LaTe and LaBr3 (in the presence of iridium) in a sealed tantalum container at elevated temperatures. The crystal structure (orthorhombic, Pnma, a = 1634.3(2), b = 435.0(1), c = 1426.6(2) pm, Z = 4, R1 (I0 > 2s(I0)) = 0.0349) is built from dicapped trigonal prisms of tellurium and bromine atoms surrounding lanthanum in two different ways. The dicapped trigonal prisms are connected via common edges to a threedimensional structure, in the same fashion as is known for the binary U3Te5. La3Te4Br is a valence compound according to (La3+)3(Te2-)4(Br-) …
Linear Trimeric Hafnium Clusters In Hf0.86(1)I3, Jan Beekhuizen, Anja V. Mudring, Gerd Meyer
Linear Trimeric Hafnium Clusters In Hf0.86(1)I3, Jan Beekhuizen, Anja V. Mudring, Gerd Meyer
Anja V. Mudring
The reduction of hafnium tetraiodide, HfI4, with aluminum at 600 °C or 850 °C in the presence of a NaI flux resulted in black single crystals of Hf0.86(1)I3. This composition corresponds well to the upper end of the non-stoichiometry range 0.89 ≤ x ≤ 1.00 previously reported for HfxI3. The crystal structure (a = 1250.3(2), c = 1999.6(3) pm, R-3m, Z = 18) is made up of hexagonal closest packed layers of iodide ions. One third of the octahedral holes would be filled as in TiI3 or ZrI3 if it were Hf1.00I3. In Hf0.86(1)I3, one out of six octahedral holes …
(B15c5)Bii3(I2): Molecular Benzo-15-Crown-5―Bii3 Complexes Bridged By Iodine Molecules To Chains, Christoph Fiolka, Mark Richter, Ingo Pantenburg, Anja V. Mudring, Gerd Meyer
(B15c5)Bii3(I2): Molecular Benzo-15-Crown-5―Bii3 Complexes Bridged By Iodine Molecules To Chains, Christoph Fiolka, Mark Richter, Ingo Pantenburg, Anja V. Mudring, Gerd Meyer
Anja V. Mudring
The reaction of bismuth triiodide with iodine and benzo-15-crown-5 in ethanol/dichloromethane yielded red single crystals of (b15c5)BiI3(I2) (monoclinic, P21/c (no. 14), a = 1376.9(1), b = 1172.7(1), c = 1700.2(2) pm, b = 115.197(6), V = 2484.1(4)·106 pm3, Z = 4). Neutral pseudo-octahedral complexes (b15c5)BiI3 are connected by secondary bonding interactions via iodine molecules to chains. Electronic structure calculations of the neutral complex (b15c5)BiI3 reveal that the compound can indeed be described as b15c5 interacting with a molecular BiI3 unit. However, bonding has to be mainly electrostatic as the interactions of the bismuth 6s lone pair with the 2p orbitals …
Europium(Iii) Fluoride Nanoparticles From Ionic Liquids: Structural, Morphological, And Luminescent Properties, Chantal Lorbeer, Joanna Cybinska, Anja V. Mudring
Europium(Iii) Fluoride Nanoparticles From Ionic Liquids: Structural, Morphological, And Luminescent Properties, Chantal Lorbeer, Joanna Cybinska, Anja V. Mudring
Anja V. Mudring
Inorganic luminescent materials (phosphors) find widespread scientific and industrial applications. For potential applications, nanoscale phosphors are favored because of the reduced scattering and the possibility to miniaturize devices. In such materials, the optical behavior is strongly dependent on impurities or defects in the crystal lattice, so that a well-defined reaction protocol with fixed parameters is compulsory to ensure the quality of the obtained material. The fast and facile conversion of europium acetate via microwave radiation with and in different tetrafluoroborate ionic liquids to oxygen-free, hexagonal EuF3 nanoparticles is investigated in detail. The study of the influence of the different reaction …