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Iowa State University

Selected Works

2012

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Electrical Resistance Of Agts–S(Ch2)N−1ch3//Ga2o3/Egain Tunneling Junctions, Ludovico Cademartiri, Martin M. Thuo, Christian A. Nijhuis, William F. Reus, Simon Tricard, Jubulani R. Barber, Rana N.S. Sodhi, Peter Brodersen, Choongik Kim, Ryan C. Chiechi, George M. Whitesides Feb 2012

Electrical Resistance Of Agts–S(Ch2)N−1ch3//Ga2o3/Egain Tunneling Junctions, Ludovico Cademartiri, Martin M. Thuo, Christian A. Nijhuis, William F. Reus, Simon Tricard, Jubulani R. Barber, Rana N.S. Sodhi, Peter Brodersen, Choongik Kim, Ryan C. Chiechi, George M. Whitesides

Martin M. Thuo

Tunneling junctions having the structure AgTS–S(CH2)n−1CH3//Ga2O3/EGaIn allow physical–organic studies of charge transport across self-assembled monolayers (SAMs). In ambient conditions, the surface of the liquid metal electrode (EGaIn, 75.5 wt % Ga, 24.5 wt % In, mp 15.7 °C) oxidizes and adsorbs―like other high-energy surfaces―adventitious contaminants. The interface between the EGaIn and the SAM thus includes a film of metal oxide, and probably also organic material adsorbed on this film; this interface will influence the properties and operation of the junctions. A combination of structural, chemical, and electrical characterizations leads to four conclusions about AgTS–S(CH2)n−1CH3//Ga2O3/EGaIn junctions. (i) The oxide is ∼0.7 …


An Analytical Model Of A Ferrite-Cored Inductor Used As An Eddy Current Probe, John R. Bowler, Yi Lu, Theodoros P. Theodoulidis Jan 2012

An Analytical Model Of A Ferrite-Cored Inductor Used As An Eddy Current Probe, John R. Bowler, Yi Lu, Theodoros P. Theodoulidis

John R. Bowler

An analytical model of an axisymmetric eddy current ferrite-cored probe above a multi-layered conducting half-space has been developed using a procedure in which the domain of the problem is truncated radially. This means that solutions can be expressed in the form of generalized Fourier-Bessel series. The expansion coefficients are found by matching the field across the interfaces between the subregions of the problem. Initially, the magnetic vector potential of a simple circular current filament is expanded in a series form. The solution is then modified to accommodate an infinitely long coaxial ferrite core, and the principle of superposition is invoked …


The Effects Of Symmetric And Asymmetric Foot Placements On Sit-To-Stand Joint Moments, Jason C. Gillette, C. A. Stevermer Jan 2012

The Effects Of Symmetric And Asymmetric Foot Placements On Sit-To-Stand Joint Moments, Jason C. Gillette, C. A. Stevermer

Jason C Gillette

The purpose of this study was to determine the effects of symmetric and asymmetric foot placements on joint moments during sit-to-stand movements. Three symmetric (foot-neutral, foot-back, and foot-intermediate) and three asymmetric foot placements (preferred stagger, nonpreferred stagger, and intermediate stagger) were tested. Standard (46 cm) and low (41 cm) seat heights were chosen to represent an average public seat height and a 10% lower seat height. Using inverse dynamics, maximum ankle plantarflexion, knee extension, hip extension, and hip abduction moments were calculated. Hip extension moments were significantly increased when using foot-neutral as compared to foot-back. Ankle plantarflexion and knee extension …


Gait Analysis Post Anterior Cruciate Ligament Reconstruction: Knee Osteoarthritis Perspective, M. Hall, C A. Stevermer, Jason C. Gillette Jan 2012

Gait Analysis Post Anterior Cruciate Ligament Reconstruction: Knee Osteoarthritis Perspective, M. Hall, C A. Stevermer, Jason C. Gillette

Jason C Gillette

Individuals with anterior cruciate ligament (ACL) reconstruction are at increased risk to develop knee osteoarthritis (OA). Gait analysis describing kinetics of the lower extremity during walking and stair use (stair ascent and stair descent) can provide insight to everyday dynamic knee joint loading. In this study, we compared lower extremity gait patterns of those with ACL reconstruction (>1 year) to a control group. Fifteen ACL reconstructed individuals and 17 healthy controls participated in this study. Knee extensor and flexor strength were assessed. Using inverse dynamics, lower extremity moments were calculated during the stance phase of walking and during two …


What Is The Risk For Metabolic Syndrome In Police Officers?, Warren D. Franke Jan 2012

What Is The Risk For Metabolic Syndrome In Police Officers?, Warren D. Franke

Warren D Franke

The report by Jayakrishnan and colleagues in this Journal is noteworthy since it provides an assessment of the presence of the metabolic syndrome and related cardiovascular risk factors in one of the largest, if not the largest, cohort of police officers to date. Two aspects of this research especially warrant comment.


Quantitative Normative Gait Data In A Large Cohort Of Ambulatory Persons With Parkinson’S Disease, Chris J. Hass, Paul Malczak, Joe Nocera, Elizabeth L. Stegemoller, Aparna Wagle Shukala, Irene Malaty, Charles E. Jacobson Iv, Michael S. Okun, Nick Mcfarland Jan 2012

Quantitative Normative Gait Data In A Large Cohort Of Ambulatory Persons With Parkinson’S Disease, Chris J. Hass, Paul Malczak, Joe Nocera, Elizabeth L. Stegemoller, Aparna Wagle Shukala, Irene Malaty, Charles E. Jacobson Iv, Michael S. Okun, Nick Mcfarland

Elizabeth L. Stegemoller

Background: Gait performance is widely evaluated to assess health status in older adult populations. While several investigators have presented normative values for spatiotemporal gait parameters drawn from older adult populations, the literature has been void of large-scale cohort studies, which are needed in order to provide quantitative, normative gait data in persons with Parkinson’s disease. The aim of this investigation was to provide reference values for clinically important gait characteristics in a large sample of ambulatory persons with Parkinson’s disease to aid both clinicians and researchers in their evaluations and treatments of gait impairment. Methodology/Principal Findings: Gait performance was collected …


In Situ Phytoplankton Analysis: There’S Plenty Of Room At The Bottom, Jeffrey S. Erickson, Nicole N. Hashemi, James M. Sullivan, Alan D. Weidemann, Frances S. Ligler Jan 2012

In Situ Phytoplankton Analysis: There’S Plenty Of Room At The Bottom, Jeffrey S. Erickson, Nicole N. Hashemi, James M. Sullivan, Alan D. Weidemann, Frances S. Ligler

Nastaran Hashemi

Approximately 70% of the earth is covered with water, within which the most dominant organism is phytoplankton. Not only is phytoplankton at the base of the marine food web, but it also fixes excess carbon dioxide and regulates sulfur on a global scale.1 Changes in phytoplankton populations have been linked to toxicity to humans and marine life, pollution, and global climate change.2 Routine monitoring of both fresh and salt water ecosystems has been taking place formany years, with consortia set up explicitly for this purpose. Consensus indicates that five categories of information are useful for early warning systems.3,4 These are …


Bacterial Isolation By Lectin-Modified Microengines, Susana Campuzano, Jahir Orozco, Daniel Kagan, Maria Guix, Wei Gao, Sirilak Sattayasamitsathit, Jonathan C. Claussen, Arben Merkoci, Joseph Wang Jan 2012

Bacterial Isolation By Lectin-Modified Microengines, Susana Campuzano, Jahir Orozco, Daniel Kagan, Maria Guix, Wei Gao, Sirilak Sattayasamitsathit, Jonathan C. Claussen, Arben Merkoci, Joseph Wang

Jonathan C. Claussen

New template-based self-propelled gold/nickel/polyaniline/platinum (Au/Ni/PANI/Pt) microtubular engines, functionalized with the Concanavalin A (ConA) lectin bioreceptor, are shown to be extremely useful for the rapid, real-time isolation of Escherichia coli (E. coli) bacteria from fuel-enhanced environmental, food, and clinical samples. These multifunctional microtube engines combine the selective capture of E. coli with the uptake of polymeric drug-carrier particles to provide an attractive motion-based theranostics strategy. Triggered release of the captured bacteria is demonstrated by movement through a low-pH glycine-based dissociation solution. The smaller size of the new polymer-metal microengines offers convenient, direct, and label-free optical visualization of the captured bacteria and …


Food Benefit And Climate Warming Potential Of Nitrogen Fertilizer Uses In China, Hanqin Tian, Chaoqun (Crystal) Lu, Jerry Melillo, Wei Ren, Yao Huang, Xiaofeng Xu, Mingliang Liu, Chi Zhang, Guangsheng Chen, Shufen Pan, Jiyuan Liu, John Reilly Jan 2012

Food Benefit And Climate Warming Potential Of Nitrogen Fertilizer Uses In China, Hanqin Tian, Chaoqun (Crystal) Lu, Jerry Melillo, Wei Ren, Yao Huang, Xiaofeng Xu, Mingliang Liu, Chi Zhang, Guangsheng Chen, Shufen Pan, Jiyuan Liu, John Reilly

Chaoqun (Crystal) Lu

Chemical nitrogen (N) fertilizer has long been used to help meet the increasing food demands in China, the top N fertilizer consumer in the world. Growing concerns have been raised on the impacts of N fertilizer uses on food security and climate change, which is lack of quantification. Here we use a carbon–nitrogen (C–N) coupled ecosystem model, to quantify the food benefit and climate consequence of agronomic N addition in China over the six decades from 1949 to 2008. Results show that N fertilizer-induced crop yield and soil C sequestration had reached their peaks, while nitrous oxide (N2O) emission continued …


Effect Of Nitrogen Deposition On China's Terrestrial Carbon Uptake In The Context Of Multifactor Environmental Changes, Chaoqun (Crystal) Lu, Hanqin Tian, Mingliang Liu, Wei Ren, Xiaofeng Xu, Guangsheng Chen, Chi Zhang Jan 2012

Effect Of Nitrogen Deposition On China's Terrestrial Carbon Uptake In The Context Of Multifactor Environmental Changes, Chaoqun (Crystal) Lu, Hanqin Tian, Mingliang Liu, Wei Ren, Xiaofeng Xu, Guangsheng Chen, Chi Zhang

Chaoqun (Crystal) Lu

The amount of atmospheric nitrogen (N) deposited on the land surface has increased globally and by nearly five times in China from 1901 to 2005. Little is known about how elevated reactive N input has affected the carbon (C) sequestration capability of China's terrestrial ecosystems, largely due to the lack of reliable data on N deposition. Here we have used a newly developed data set of historical N deposition at a spatial resolution of 10 km × 10 km in combination with other gridded historical information on climate, atmospheric composition, land use, and land management practices to drive a process-based …


Contemporary And Projected Biogenic Fluxes Of Methane And Nitrous Oxide In North American Terrestrial Ecosystems, Hanqin Tian, Chaoqun (Crystal) Lu, Guangsheng Chen, Bo Tao, Shufen Pan, Stephen J. Del Grosso, Xiaofeng Xu, Lori Bruhwiler, Steven C. Wofsy, Eric A. Kort, Stephen A. Prior Jan 2012

Contemporary And Projected Biogenic Fluxes Of Methane And Nitrous Oxide In North American Terrestrial Ecosystems, Hanqin Tian, Chaoqun (Crystal) Lu, Guangsheng Chen, Bo Tao, Shufen Pan, Stephen J. Del Grosso, Xiaofeng Xu, Lori Bruhwiler, Steven C. Wofsy, Eric A. Kort, Stephen A. Prior

Chaoqun (Crystal) Lu

Accurately estimating biogenic methane (CH4) and nitrous oxide (N2O) fluxes in terrestrial ecosystems is critical for resolving global budgets of these greenhouse gases (GHGs) and continuing to mitigate climate warming. Here, we assess contemporary biogenic CH4 and N2O budgets and probable climate-change-related impacts on CH4 and N2O emissions in terrestrial North America. Multi-approach estimations show that, during 1990–2010, biogenic CH4 emissions ranged from 0.159 to 0.502 petagrams of carbon dioxide (CO2) equivalents per year (Pg CO2eq yr–1, where 1 Pg = 1 × 1015 g) and N2O emissions ranged from 0.802 to 1.016 Pg CO2eq yr–1, which offset 47–166% of …


Does Immunocontraception In Feral Horses (Equus Caballus) Extend Reproductive Cycling Beyond The Normal Breeding Season?, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein Jan 2012

Does Immunocontraception In Feral Horses (Equus Caballus) Extend Reproductive Cycling Beyond The Normal Breeding Season?, Cassandra M.V. Nuñez, James S. Adelman, Daniel I. Rubenstein

Cassandra M.V. Nuñez

Although the physiological effects of immunocontraceptive treatment with porcine zona pellucida (PZP) have been well studied, little is known about PZP’s effects on the scheduling of reproductive cycling. Recent behavioral research has suggested that recipients of PZP extend the receptive breeding period into what is normally the non-breeding season. To determine if this is the case, we compiled foaling data from wild horses (Equus caballus) living on Shackleford Banks, North Carolina for 4 years pre- and 8 years post-contraception management with PZP (pre-contraception, n = 65 births from 45 mares; post-contraception, n = 97 births from 46 mares). Gestation lasts …


Melting Point Suppression In New Lanthanoid(Iii) Ionic Liquids By Trapping Of Kinetic Polymorphs: An In Situsynchrotron Powder Diffraction Study, Anthony S.R. Chesman, Mei Yang, Bert Mallick, Tamsyn M. Ross, Ian A. Gass, Glen B. Deacon, Stuart R. Batten, Anja V. Mudring Jan 2012

Melting Point Suppression In New Lanthanoid(Iii) Ionic Liquids By Trapping Of Kinetic Polymorphs: An In Situsynchrotron Powder Diffraction Study, Anthony S.R. Chesman, Mei Yang, Bert Mallick, Tamsyn M. Ross, Ian A. Gass, Glen B. Deacon, Stuart R. Batten, Anja V. Mudring

Anja V. Mudring

he inclusion of lanthanoids in ionic liquids (ILs) offers an ideal route to incorporate their unique luminescent and magnetic properties into a bulk solution.1,2 However, lanthanoid compounds often exhibit a poor solubility in commonly used ILs because the IL anions are typically very weakly coordinating, prohibiting the simple dissolution of a lanthanoid salt by complexation to any beneficial extent.2 One strategy used to achieve high lanthanoid concentrations is to incorporate the lanthanoid cation directly into an anion that will form ILs.3 This is best accomplished by employing a ligand which readily coordinates to a lanthanoid atom and possesses properties, such …


Mox/Cnts Hetero-Structures For Gas Sensing Applications: Role Of Cnts Defects, G. Neri, S. G. Leonardi, N. Donato, C. Marichy, Jean-Philippe Tessonnier, M.-G. Willinger, Kyeong-Hwan Lee, N. Pinna Jan 2012

Mox/Cnts Hetero-Structures For Gas Sensing Applications: Role Of Cnts Defects, G. Neri, S. G. Leonardi, N. Donato, C. Marichy, Jean-Philippe Tessonnier, M.-G. Willinger, Kyeong-Hwan Lee, N. Pinna

Jean-Philippe Tessonnier

The preparation, characterization and sensing properties of CNT composites with a thin metal oxide (MOx) surface layer is presented. Atomic layer deposition (ALD) was applied for the coating of the inner and outer CNTs walls with thin films of ZnO and SnO2 of precisely controlled thicknesses. Differently treated CNTs with different degree of surface functionalization were used as support for the oxide films. The sensing properties of the obtained composite materials towards NO2 were investigated and related to the morphological and microstructural characteristics of both the coating and support. SnO2-based composites on CNTs treated at 700 °C show enhanced performance …


Analysis Of The Risks And Benefits Of Flight Deck Adaptive Systems, Michael C. Dorneich, William Rogers, Stephen D. Whitlow, Robert Demers Jan 2012

Analysis Of The Risks And Benefits Of Flight Deck Adaptive Systems, Michael C. Dorneich, William Rogers, Stephen D. Whitlow, Robert Demers

Michael C. Dorneich

The objectives of this work were to identify human performance risks and benefits of adaptive systems through a systematic analysis and heuristic evaluation of adaptive system component types and characteristics. As flight deck automated systems have more access to aircraft data, sensor data, stored databases, communicated information, and real time flight crew inputs, as well as more ability to process that information in sophisticated ways to identify situational priorities and context, it is becoming more realistic for those automated systems to adapt their behavior based on context. Automated systems that can make such changes on their own are called adaptive …


Phosphate Protected Fluoride Nano-Phosphors, Joanna Cybinska, Chantal Lorbeer, Anja V. Mudring Jan 2012

Phosphate Protected Fluoride Nano-Phosphors, Joanna Cybinska, Chantal Lorbeer, Anja V. Mudring

Anja V. Mudring

A fast and easy 2-in-1 step microwave reaction procedure to phosphate coated nanofluorides allows for the formation of phosphate protected fluoride nanoparticles from simple lanthanide precursors in ionic liquids. The phosphate shell efficiently prevents the fluoride particle from decomposition in an atmosphere (containing oxygen and water) at elevated temperatures.


Considering Etiquette In The Design Of An Adaptive System, Michael C. Dorneich, Patricia May Ververs, Santosh Mathan, Stephen Whitlow, Caroline C. Hayes Jan 2012

Considering Etiquette In The Design Of An Adaptive System, Michael C. Dorneich, Patricia May Ververs, Santosh Mathan, Stephen Whitlow, Caroline C. Hayes

Michael C. Dorneich

In this article, the authors empirically assess the costs and benefits of designing an adaptive system to follow social conventions regarding the appropriateness of interruptions. Interruption management is one area within the larger topic of automation etiquette. The authors tested these concepts in an outdoor environment using the Communications Scheduler, a wearable adaptive system that classifies users' cognitive state via brain and heart sensors and adapts its interactions. Designed to help dismounted soldiers, it manages communications in much the same way as a good administrative assistant. Depending on a combination of message priority, user workload, and system state, it decides …


The Use Of A Ditopic Gd(Iii) Paramagnetic Probe For Investigating Α-Bungarotoxin Surface Accessibility, Andrea Bernini, Ottavia Spiga, Vincenzo Venditti, Filippo Prischi, Mauro Botta, Gianluca Croce, Angela Pui-Ling Tong, Wing-Talk Wong, Neri Niccolai Jan 2012

The Use Of A Ditopic Gd(Iii) Paramagnetic Probe For Investigating Α-Bungarotoxin Surface Accessibility, Andrea Bernini, Ottavia Spiga, Vincenzo Venditti, Filippo Prischi, Mauro Botta, Gianluca Croce, Angela Pui-Ling Tong, Wing-Talk Wong, Neri Niccolai

Vincenzo Venditti

Protein surface accessibility is a critical parameter which drives all intermolecular interaction processes. In this respect a big deal of information has been derived by analyzing paramagnetic perturbation profiles obtained from NMR protein spectra, particularly in the case that the effects due to different soluble paramagnets can be compared. Here Gd2L7, a neutral ditopic paramagnetic NMR probe, has been characterized in terms of structure and relaxivity and its paramagnetic perturbations on α-bungarotoxin CαH signals in 1H–13C HSQC (heteronuclear single quantum coherence) spectra have been analyzed. Then, these signal attenuations have been compared with the ones previously obtained in the presence …


An Efficient Protocol For Incorporation Of An Unnatural Amino Acid In Perdeuterated Recombinant Proteins Using Glucose-Based Media, Vincenzo Venditti, Nicolas L. Fawzi, G. Marius Clore Jan 2012

An Efficient Protocol For Incorporation Of An Unnatural Amino Acid In Perdeuterated Recombinant Proteins Using Glucose-Based Media, Vincenzo Venditti, Nicolas L. Fawzi, G. Marius Clore

Vincenzo Venditti

The in vivo incorporation of unnatural amino acids into proteins is a well-established technique requiring an orthogonal tRNA/aminoacyl-tRNA synthetase pair specific for the unnatural amino acid that is incorporated at a position encoded by a TAG amber codon. Although this technology provides unique opportunities to engineer protein structures, poor protein yields are usually obtained in deuterated media, hampering its application in the protein NMR field. Here, we describe a novel protocol for incorporating unnatural amino acids into fully deuterated proteins using glucose-based media (which are relevant to the production, for example, of amino acid-specific methyl-labeled proteins used in the study …


Minimization And Maximization Techniques: Assessing The Perceived Consequences Of Confessing And Confession Diagnosticity, Allyson J. Horgan, Melissa B. Russano, Christian A. Meissner, Jacqueline R. Evans Jan 2012

Minimization And Maximization Techniques: Assessing The Perceived Consequences Of Confessing And Confession Diagnosticity, Allyson J. Horgan, Melissa B. Russano, Christian A. Meissner, Jacqueline R. Evans

Christian A. Meissner, Ph.D.

Identifying interrogation strategies that minimize the likelihood of obtaining false information, without compromising the ability to elicit true information, is a challenge faced by both law enforcement and scientists. Previous research suggests that minimization and maximization techniques may be perceived by a suspect as an expectation of leniency and a threat of harsher punishment, respectively, and that these approaches may be associated with false confessions. The current studies examine whether it is possible to distinguish between minimization and maximization techniques that do or do not influence a suspect’s perceptions of the consequences of confessing. Results indicate that techniques that manipulate …


Chemically Modified Multi-Walled Carbon Nanotubes (Mwcnts) With Anchored Acidic Groups, Nuruzatulifah Bt Asari Mansor, Jean-Philippe Tessonnier, Ali Rinaldi, Sylvia Reiche, M. G. Kutty Jan 2012

Chemically Modified Multi-Walled Carbon Nanotubes (Mwcnts) With Anchored Acidic Groups, Nuruzatulifah Bt Asari Mansor, Jean-Philippe Tessonnier, Ali Rinaldi, Sylvia Reiche, M. G. Kutty

Jean-Philippe Tessonnier

Surface functionalization of multi-walled carbon nanotubes (MWCNTs) was carried out using a gas phase treatment in a Universal Temperature Program (UTP) reactor by flowing SO 3 gas onto the CNTs while being heated at different temperatures. The functionalized nanotubes were characterized using X-ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FT-IR) and Raman spectroscopy. The amount of oxyen and sulfur containing groups was determined by acid-base titration. The titration results were in good agreement with elemental analysis using X-ray fluorescence. FTIR analysis showed the presence of oxygen and sulfur containing groups, S=O, C-S, C=O and-COOH. Raman spectroscopy confirmed that oxygen and …


Conformational Selection And Substrate Binding Regulate The Monomer/Dimer Equilibrium Of The C-Terminal Domain Of Escherichia Coli Enzyme I, Vincenzo Venditti, G. Marius Clore Jan 2012

Conformational Selection And Substrate Binding Regulate The Monomer/Dimer Equilibrium Of The C-Terminal Domain Of Escherichia Coli Enzyme I, Vincenzo Venditti, G. Marius Clore

Vincenzo Venditti

The bacterial phosphotransferase system (PTS) is a signal transduction pathway that couples phosphoryl transfer to active sugar transport across the cell membrane. The PTS is initiated by the binding of phosphoenolpyruvate (PEP) to the C-terminal domain (EIC) of enzyme I (EI), a highly conserved protein that is common to all sugar branches of the PTS. EIC exists in a dynamic monomer/dimer equilibrium that is modulated by ligand binding and is thought to regulate the overall PTS. Isolation of EIC has proven challenging, and conformational dynamics within the EIC domain during the catalytic cycle are still largely unknown. Here, we present …


Measuring Changes In International Production From A Disruption: Case Study Of The Japanese Earthquake And Tsunami, Cameron A. Mackenzie, Joost R. Santos, Kash Barker Jan 2012

Measuring Changes In International Production From A Disruption: Case Study Of The Japanese Earthquake And Tsunami, Cameron A. Mackenzie, Joost R. Santos, Kash Barker

Cameron A. MacKenzie

The earthquake and tsunami that struck Japan on March 11, 2011 caused a tremendous loss of life and property. The disaster also disrupted global supply chains, which was blamed for anemic growth in the global economy. A multiregional input-output model can quantify the international impacts on production due to changes in demand from companies reducing their orders because of a disruption. Using the input-output model to conceptualize a supply chain, we present a unique method for calculating indirect production losses caused by disabled production facilities. Methods for calculating the possible transfer of demand to industries in other countries are also …


Determination Of The Solubilizing Character Of 1-Methoxyethyl-1- Methylpiperidinium Tris(Pentafluoroethyl)Trifluorophosphate Based On The Abraham Solvation Parameter Model, Pamela Twu, Jared L. Anderson, Timothy W. Stephens, William E. Acree Jr., Michael H. Abraham Jan 2012

Determination Of The Solubilizing Character Of 1-Methoxyethyl-1- Methylpiperidinium Tris(Pentafluoroethyl)Trifluorophosphate Based On The Abraham Solvation Parameter Model, Pamela Twu, Jared L. Anderson, Timothy W. Stephens, William E. Acree Jr., Michael H. Abraham

Jared L. Anderson

Chromatographic retention data were measured for a chemically diverse set of organic solutes on an anhydrous 1-methoxyethyl-1-methylpiperidinium tris(pentafluoroethyl)trifluorophosphate, ([MeoeMPip]+ [FAP]–), stationary phase at both 323 K and 353 K. The experimental retention factors were combined with previously published thermodynamic data and gas-to-water partition coefficient data to yield gas-to-anhydrous ionic liquid (IL) and water-to-anhydrous IL partition coefficients. The three sets of partition coefficient data were analyzed in accordance with the Abraham model. The Abraham model correlations that were determined in the present study describe the observed gas-to-([MeoeMPip]+[FAP]–) (log K) and water-to-([MeoeMPip]+[FAP]–) (log P) partition coefficient data to within average standard deviations …


Lanthanide Coordination Polymers With Tetrafluoroterephthalate As A Bridging Ligand: Thermal And Optical Properties, Christiane Seidel, Chantal Lorbeer, Joanna Cyninska, Anja V. Mudring, Uwe Ruschewitz Jan 2012

Lanthanide Coordination Polymers With Tetrafluoroterephthalate As A Bridging Ligand: Thermal And Optical Properties, Christiane Seidel, Chantal Lorbeer, Joanna Cyninska, Anja V. Mudring, Uwe Ruschewitz

Anja V. Mudring

Seven new coordination polymers ∞2[Ln(tfBDC)(NO3)(DMF)2]·DMF (Ln3+ = Ce, Pr, Nd, Sm, Dy, Er, Yb) with the perfluorinated linker ligand tetrafluoroterephthalate (tfBDC2−) have been synthesized. Their crystal structures consist of layers (44 nets) weakly bound by van der Waals interactions. In addition, differential thermal analysis/thermogravimetry (DTA/TG) curves, as well as absorption and emission spectra, have been recorded for all compounds.


Betaine Chloride-Betaine Tetrachloridoferrate(Iii)—An Ionic Liquid Related Crystal Structure Governed By The Pearson Concept, Anja V. Mudring, Tobias Backer Jan 2012

Betaine Chloride-Betaine Tetrachloridoferrate(Iii)—An Ionic Liquid Related Crystal Structure Governed By The Pearson Concept, Anja V. Mudring, Tobias Backer

Anja V. Mudring

The first betaine chloride tetrachloroidoferrate(III) double salt, (Hbet)2Cl[FeCl4] = (Hbet)Cl·(Hbet)[FeCl4], was obtained from a solution of betaine hydrochloride (HbetCl) and FeCl3∙6 H2O in water. The crystal structure (orthorhombic, Pbcm, a = 6.2717(13), b = 12.841(3), c = 25.693(5) Å, Z = 4) is characterized by layers of tetrachloridoferrate(III) anions separated by chloride-bridged, H-bond mediated cationic (Hbet) dimers. The hydrogen bonding network in the crystal structure follows the Pearson HSAB (hard acid-soft base) concept: According to the Pearson concept, the chloride anions show high affinity to the carboxyl group (hard acid and base), and the tetrachloroidoferrate(III) anion preferentially interacts with the …


Ultrasound-Assisted Synthesis Of Mesoporous Β-Ni(Oh)2 And Nio Nano-Sheets Using Ionic Liquids, Tarek Alammar, Osama Shekhah, Jonas Wohlgemuth, Anja V. Mudring Jan 2012

Ultrasound-Assisted Synthesis Of Mesoporous Β-Ni(Oh)2 And Nio Nano-Sheets Using Ionic Liquids, Tarek Alammar, Osama Shekhah, Jonas Wohlgemuth, Anja V. Mudring

Anja V. Mudring

Via a facile ultrasound synthesis from nickel acetate and sodium hydroxide with ionic liquids as the solvent and template it is possible to obtain nano-β-Ni(OH)2 of various dimensionalities depending on the reaction conditions with the ionic liquid (IL) being the most important factor. Scanning electron microscopy (SEM) imaging showed β-Ni(OH)2 to form as nanosheets, nanorods and nanospheres depending on the IL. ILs with strong to moderate hydrogen bonding capability like [C3mimOH][Tf2N] (1-(3-hydroxypropyl)-3-methylimidazolium bis(trifluoromethanesulfonylamide)), [C4mim][Tf2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonylamide)) and [Edimim][Tf2N] (1-ethyl-2,3-diemethylimidazolium bis(trifluoromethanesulfonylamide)) lead to the formation of nanosheets whilst [Py4][Tf2N] (butyl-pyridinium bis(trifluoromethanesulfonylamide)) leads to nanoparticles and [N1888][Tf2N] (methyltrioctylammonium bis(trifluoromethanesulfonylamide)) to nanorods. Subsequent …


Analysis Of Arc-Electrode Capacitive Sensors For Characterization Of Dielectric Cylindrical Rods, Tianming Chen, Nicola Bowler, John R. Bowler Jan 2012

Analysis Of Arc-Electrode Capacitive Sensors For Characterization Of Dielectric Cylindrical Rods, Tianming Chen, Nicola Bowler, John R. Bowler

John R. Bowler

An arc-electrode capacitive sensor has been developed for quantitative characterization of permittivity of cylindrical dielectric rods. The material property of the cylindrical test piece can be inversely determined from the sensor output capacitance based on a theoretical model. For the modeling process, the electrostatic Green’s function due to a point source exterior to a dielectric rod is derived. The sensor output capacitance is numerically calculated using the method of moments (MoM), in which the integral equation is set up based on the electrostatic Green’s function. Numerical calculations on sensor configuration optimization are performed. Calculations also demonstrate the quantitative relationship between …


Materials For Diabetes Therapeutics, Kaitlin M. Bratlie, Roger L. York, Michael A. Invernale, Robert Langer, Daniel G. Anderson Jan 2012

Materials For Diabetes Therapeutics, Kaitlin M. Bratlie, Roger L. York, Michael A. Invernale, Robert Langer, Daniel G. Anderson

Kaitlin M. Bratlie

This review is focused on the materials and methods used to fabricate closedloop systems for type 1 diabetes therapy. Herein, we give a brief overview of current methods used for patient care and discuss two types of possible treatments and the materials used for these therapies-(i) artificial pancreases, comprised of insulin producing cells embedded in a polymeric biomaterial, and (ii) totally synthetic pancreases formulated by integrating continuous glucose monitors with controlled insulin release through degradable polymers and glucose-responsive polymer systems. Both the artificial and the completely synthetic pancreas have two major design requirements: the device must be both biocompatible and …


Scaling Metagenome Sequence Assembly With Probabilistic De Bruijn Graphs, Jason Pell, Rosangela Canino-Koning, Adina Howe, James Tiedje, C T. Brown Jan 2012

Scaling Metagenome Sequence Assembly With Probabilistic De Bruijn Graphs, Jason Pell, Rosangela Canino-Koning, Adina Howe, James Tiedje, C T. Brown

Adina Howe

Deep sequencing has enabled the investigation of a wide range of environmental microbial ecosystems, but the high memory requirements for de novo assembly of short-read shotgun sequencing data from these complex populations are an increasingly large practical barrier. Here we introduce a memory-efficient graph representation with which we can analyze the k-mer connectivity of metagenomic samples. The graph representation is based on a probabilistic data structure, a Bloom filter, that allows us to efficiently store assembly graphs in as little as 4 bits per k-mer, albeit inexactly. We show that this data structure accurately represents DNA assembly graphs in low …