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Iowa State University

Selected Works

2013

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Articles 31 - 60 of 63

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Educational Needs Asessment And Practices Of Grocery Store Food Handlers Through Survey And Observational Data Collection, Lynn A. Robertson, Renee R. Boyer, Benjamin J. Chapman, Joseph D. Eifert, Nancy K. Franz Mar 2013

Educational Needs Asessment And Practices Of Grocery Store Food Handlers Through Survey And Observational Data Collection, Lynn A. Robertson, Renee R. Boyer, Benjamin J. Chapman, Joseph D. Eifert, Nancy K. Franz

Nancy K. Franz

Grocery store associates in deli/bakery departments prepare and serve an increasing number of ready-to eat (RTE) foods and full meals. The shift to more convenience foods and take-home meals highlights the need for effective food safety training programs in retail grocery establishments to prevent foodborne illness. Through qualitative and quantitative methods, food safety knowledge, training preferences, needs, and current practices of grocery stores deli/bakery food handlers in Southwest and Southern Virginia were explored. Deli employees (n ¼ 78) completed a 34 question survey eliciting information on demographics, food safety training needs, preferences and knowledge. In an additional phase of this …

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Blended Isogeometric Shells, D. J. Benson, S. Hartmann, Y. Bazilevs, Ming-Chen Hsu, T.J.R. Hughes Mar 2013

Blended Isogeometric Shells, D. J. Benson, S. Hartmann, Y. Bazilevs, Ming-Chen Hsu, T.J.R. Hughes

Ming-Chen Hsu

We propose a new isogeometric shell formulation that blends Kirchhoff–Love theory with Reissner–Mindlin theory. This enables us to reduce the size of equation systems by eliminating rotational degrees of freedom while simultaneously providing a general and effective treatment of kinematic constraints engendered by shell intersections, folds, boundary conditions, the merging of NURBS patches, etc. We illustrate the blended theory’s performance on a series of test problems.

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Into The Breach: The Career Of David B. Gracy Ii, Kimberly D. Anderson Mar 2013

Into The Breach: The Career Of David B. Gracy Ii, Kimberly D. Anderson

Kimberly D. Anderson

David B. Gracy II has had a significant influence on the development of archival practice in the United States. Through his service in and leadership of the Society of American Archivists, and his activism regionally in both Texas and Georgia, Gracy has shaped the profession and inspired several generations of students and future archivists. This paper explores the development of Gracy’s career and the impact it has had on archives, archivists, and the field of archival enterprise.

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Structural Health Monitoring System And Method Using Soft Capacitive Sensing Materials, Simon Laflamme, Matthias Kollosche, Guggi H. R. Kofod Feb 2013

Structural Health Monitoring System And Method Using Soft Capacitive Sensing Materials, Simon Laflamme, Matthias Kollosche, Guggi H. R. Kofod

Simon Laflamme

A structural health monitoring system is provided to diagnose and localize crack damage on structural elements. The system uses one or more capacitive sensor assemblies that employ a soft dielectric material. The system can be applied over a large area as a sensing skin, allowing the presence of cracks to be localized.

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45-Year Trends In Women's Use Of Time And Household Management Energy Expenditure., Edward Archer, Robin P. Shook, Diana M. Thomas, Timothy S. Church, Peter T. Katzmarzyk, James R. Hebert, Kerry L. Mciver, Gregory A. Hand, Carl J. Lavie, Steven N. Blair Feb 2013

45-Year Trends In Women's Use Of Time And Household Management Energy Expenditure., Edward Archer, Robin P. Shook, Diana M. Thomas, Timothy S. Church, Peter T. Katzmarzyk, James R. Hebert, Kerry L. Mciver, Gregory A. Hand, Carl J. Lavie, Steven N. Blair

Robin Shook

Context: Relationships between socio-environmental factors and obesity are poorly understood due to a dearth of longitudinal population-level research. The objective of this analysis was to examine 45-year trends in time-use, household management (HM) and energy expenditure in women. Design and Participants: Using national time-use data from women 19–64 years of age, we quantified time allocation and household management energy expenditure (HMEE) from 1965 to 2010. HM was defined as the sum of time spent in food preparation, post-meal cleaning activities (e.g., dish-washing), clothing maintenance (e.g., laundry), and general housework. HMEE was calculated using body weights from national surveys and metabolic …

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Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown Feb 2013

Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown

Michael J Weber Dr

Resource pulses and subsidies can supply ecosystems with an important source of nutrients that supports additional productivity at multiple trophic levels. Common carp Cyprinus carpio provide ecosystems with a continuous nutrient subsidy through bioturbation and excretion but may also initiate a nutrient pulse through carcass decomposition. We examined how continuous (common carp foraging and excretion), pulsed (carcass decomposition) and disrupted (carp introduced and then removed) nutrient subsidies differed in their ability to alter nutrient availability, ecosystem productivity and stability and energy flow. Nitrogen and phosphorus availability and primary production were highest in pulsed, intermediate in continuous and lowest for disrupted …

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Joint Base Station Clustering And Beamformer Design For Partial Coordinated Transmission In Heterogeneous Networks, Mingyi Hong, Ruoyu Sun, Hadi Baligh, Zhi-Quan Luo Feb 2013

Joint Base Station Clustering And Beamformer Design For Partial Coordinated Transmission In Heterogeneous Networks, Mingyi Hong, Ruoyu Sun, Hadi Baligh, Zhi-Quan Luo

Mingyi Hong

We consider the interference management problem in a multicell MIMO heterogeneous network. Within each cell there is a large number of distributed micro/pico base stations (BSs) that can be potentially coordinated for joint transmission. To reduce coordination overhead, we consider user-centric BS clustering so that each user is served by only a small number of (potentially overlapping) BSs. Thus, given the channel state information, our objective is to jointly design the BS clustering and the linear beamformers for all BSs in the network. In this paper, we formulate this problem from a {sparse optimization} perspective, and propose an efficient algorithm …

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Method And System For Lactose-Free Or Lactose-Reduced Milk And Associated Products, Production Thereof, And Associated Processes, Joseph H. Hotchkiss, Joey Talbert Jan 2013

Method And System For Lactose-Free Or Lactose-Reduced Milk And Associated Products, Production Thereof, And Associated Processes, Joseph H. Hotchkiss, Joey Talbert

Joey Talbert

A system and method capable of hydrolyzing lactose, where the system includes a support formed from a functionalized hydrophobic polymer that is covalently linked to a hydrophilic molecule covalently that is, in turn, covalently linked to an enzyme such as lactose. The method includes the steps of functionalizing a hydrophobic polymer support, covalently linking a hydrophilic molecule to said functionalized polymer support, and covalently linking an enzyme such as lactase to said hydrophilic molecule. The system and method generally relate to the field of food science and engineering and, more particularly to dairy-based food products and their production including solutions …

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Preventing Graduate Student Heroic Suicide In Community-Based Research: A Tale Of Two Committees, Nancy K. Franz Dr. Jan 2013

Preventing Graduate Student Heroic Suicide In Community-Based Research: A Tale Of Two Committees, Nancy K. Franz Dr.

Nancy K. Franz

Graduate students are increasingly interested in community-based research and public scholarship. However, they often struggle to find faculty research mentors who fully understand or have been personally involved with this type of research and related scholarship. In fact, some graduate students are advised by graduate committee members to refrain from working with communities and community stakeholders. Graduate students also experience few opportunities to develop skills and knowledge for community-based scholarship. It is clear that graduate students interested in community-based research need tools to navigate these dynamics. This article proposes a research stakeholder advisory committee as a successful tool for graduate …

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Out-Of-Classroom Experiences: Bridging The Disconnect Between The Classroom, The Engineering Workforce, And Ethical Development, Brian A. Burt, Donald D. Carpenter, Matthew A. Holsapple, Cynthia J. Finelli, Rob M. Bielby, Janel A. Sutkus, Trevors S. Harding Jan 2013

Out-Of-Classroom Experiences: Bridging The Disconnect Between The Classroom, The Engineering Workforce, And Ethical Development, Brian A. Burt, Donald D. Carpenter, Matthew A. Holsapple, Cynthia J. Finelli, Rob M. Bielby, Janel A. Sutkus, Trevors S. Harding

Brian Burt A.

The extant research on engineering ethics instruction shows that students receive ethics instruction within the engineering curricula. Unfortunately, the methods used in engineering undergraduate classrooms are described as ‘‘abstract’’ and have mixed results related to impacting students’ ethical development. Thus, exploring how out-of-classroom experiences—as a curricular alternative—influences students’ ethical development is warranted. This is an exploratory investigation to determine how out-of-classroom experiences influence students’ ethical development. The authors define ethical development using three constructs: knowledge of ethics, ethical reasoning, and ethical behavior. We draw upon a conceptual model that suggests students’ ethical development is impacted by what takes place inside …

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Derivative Estimation With Local Polynomial Fitting, Kris De Brabanter, Jos De Brabanter, Bart De Moor, Irene Gijbels Jan 2013

Derivative Estimation With Local Polynomial Fitting, Kris De Brabanter, Jos De Brabanter, Bart De Moor, Irene Gijbels

Kris De Brabanter

We present a fully automated framework to estimate derivatives nonparametrically without estimating the regression function. Derivative estimation plays an important role in the exploration of structures in curves (jump detection and discontinuities), comparison of regression curves, analysis of human growth data, etc. Hence, the study of estimating derivatives is equally important as regression estimation itself. Via empirical derivatives we approximate the qth order derivative and create a new data set which can be smoothed by any nonparametric regression estimator. We derive L1 and L2 rates and establish consistency of the estimator. The new data sets created by this technique are …

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Biophotonic Logic Devices Based On Quantum Dots And Temporally-Staggered Forster Energy Transfer Relays, Jonathan C. Claussen, W. Russ Algar, Niko Hildebrandt, Kimihiro Susumu, Mario G. Ancona, Igor L. Medintz Jan 2013

Biophotonic Logic Devices Based On Quantum Dots And Temporally-Staggered Forster Energy Transfer Relays, Jonathan C. Claussen, W. Russ Algar, Niko Hildebrandt, Kimihiro Susumu, Mario G. Ancona, Igor L. Medintz

Jonathan C. Claussen

Integrating photonic inputs/outputs into unimolecular logic devices can provide significantly increased functional complexity and the ability to expand the repertoire of available operations. Here, we build upon a system previously utilized for biosensing to assemble and prototype several increasingly sophisticated biophotonic logic devices that function based upon multistep Förster resonance energy transfer (FRET) relays. The core system combines a central semiconductor quantum dot (QD) nanoplatform with a long-lifetime Tb complex FRET donor and a near-IR organic fluorophore acceptor; the latter acts as two unique inputs for the QD-based device. The Tb complex allows for a form of temporal memory by …

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Predicting Modes Of Toxic Action From Chemical Structure, Steven P. Bradbury, Christine L. Russom, Steven J. Broderius, Dean J. Hammermeister, Robert A. Drummond, Gilman D. Veith Jan 2013

Predicting Modes Of Toxic Action From Chemical Structure, Steven P. Bradbury, Christine L. Russom, Steven J. Broderius, Dean J. Hammermeister, Robert A. Drummond, Gilman D. Veith

Steven P. Bradbury

Like many of the papers in the Environmental Toxicology and Chemistry “Top 100” list, the development of the fathead minnow database [1] and the assignment of modes of action to the 617 chemicals therein resulted from a comprehensive research effort by a multidisciplinary team of researchers with expertise in quantitative structure–activity relationship (QSAR) modeling, chemistry, toxicokinetics, joint toxicity of chemical mixtures, and behavioral and aquatic toxicology. The fathead minnow database was the culmination of the US Environmental Protection Agency’s (USEPA) QSAR research program, which spanned nearly 20 yr, a rare program because many research planning efforts typically run within a …

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When Wet Gets Wetter: Decoupling Of Moisture, Redox Biogeochemistry, And Greenhouse Gas Fluxes In A Humid Tropical Forest Soil, Steven J. Hall, William H. Mcdowell, Whendee L. Silver Jan 2013

When Wet Gets Wetter: Decoupling Of Moisture, Redox Biogeochemistry, And Greenhouse Gas Fluxes In A Humid Tropical Forest Soil, Steven J. Hall, William H. Mcdowell, Whendee L. Silver

Steven J. Hall

Upland humid tropical forest soils are often characterized by fluctuating redox dynamics that vary temporally and spatially across the landscape. An increase in the frequency and intensity of rainfall events with climate change is likely to affect soil redox reactions that control the production and emissions of greenhouse gases. We used a 24-day rainfall manipulation experiment to evaluate temporal and spatial trends of surface soil (0–20 cm) redox-active chemical species and greenhouse gas fluxes in the Luquillo Experimental Forest, Puerto Rico. Treatments consisted of a high rainfall simulation (60 mm day-1), a fluctuating rainfall regime, and a control. Water addition …

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Mild Yet Phase-Selective Preparation Of Tio2 Nanoparticles From Ionic Liquids – A Critical Study, Tarek Alammar, Heshmat Noei, Yuemin Wang, Anja V. Mudring Jan 2013

Mild Yet Phase-Selective Preparation Of Tio2 Nanoparticles From Ionic Liquids – A Critical Study, Tarek Alammar, Heshmat Noei, Yuemin Wang, Anja V. Mudring

Anja V. Mudring

The phase selective synthesis of nanocrystalline TiO2, titania, in ionic liquids (ILs) is explored. The influence not only of the IL but also of the Ti-precursor, pH, and temperature is investigated. Sonochemical synthesis, microwave synthesis and conventional heating are compared. In the case of Ti(OiPr)4 (OiPr ¼ isopropyl) as the Ti-source the ILs [C4mim][Tf2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide), [C3mimOH][Tf2N] (1-(3-hydroxypropyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)amide), [C4Py]- [Tf2N] (butylpyridinium bis(trifluoromethanesulfonyl)amide), [N1888][Tf2N] (methyltrioctylammonium bis- (trifluoromethanesulfonyl)amide), and [P66614][Tf2N] (tetradecyltrihexyl phosphonium bis(trifluoromethanesulfonyl) amide) led at ambient temperature to TiO2 in the form of anatase. The morphology of nano-anatase is controlled by the IL cation. Anatase nanospheres with a crystal size …

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Tin Dioxide–Carbon Heterostructures Applied To Gas Sensing: Structure-Dependent Properties And General Sensing Mechanism, Catherine Marichy, Patricia A. Russo, Mariangela Latino, Jean-Philippe Tessonnier, Marc-Georg Willinger, Nicola Donato, Giovanni Neri, Nicola Pinna Jan 2013

Tin Dioxide–Carbon Heterostructures Applied To Gas Sensing: Structure-Dependent Properties And General Sensing Mechanism, Catherine Marichy, Patricia A. Russo, Mariangela Latino, Jean-Philippe Tessonnier, Marc-Georg Willinger, Nicola Donato, Giovanni Neri, Nicola Pinna

Jean-Philippe Tessonnier

Carbon materials such as carbon nanotubes (CNTs), graphene, and reduced graphene oxide (RGO) exhibit unique electrical properties, which are also influenced by the surrounding atmosphere. They are therefore promising sensing materials. Despite the existence of studies reporting the gas-sensing properties of metal oxide (MOx) coated nanostructured carbon, an incomplete understanding of their sensing mechanism remains. Here we report a systematic study on the preparation, characterization, and sensing properties of CNT and RGO composites with SnO2 coating. Atomic layer deposition (ALD) was applied to the conformal coating of the inner and outer walls of CNTs with thin films of SnO2 of …

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Yttrium(Iii) Oxomolybdates(Vi) As Potential Host Materials For Luminescence Applications: An Investigation Of Eu3+-Doped Y2[Moo4]3 And Y2[Moo4]2[Mo2o7], Sonja Laufer, Sabine Strobel, Thomas Schleid, Joanna Cybinska, Anja V. Mudring, Ingo Hartenbach Jan 2013

Yttrium(Iii) Oxomolybdates(Vi) As Potential Host Materials For Luminescence Applications: An Investigation Of Eu3+-Doped Y2[Moo4]3 And Y2[Moo4]2[Mo2o7], Sonja Laufer, Sabine Strobel, Thomas Schleid, Joanna Cybinska, Anja V. Mudring, Ingo Hartenbach

Anja V. Mudring

Two ternary yttrium(III) oxomolybdates(VI) are investigated, both structurally and spectroscopically. The crystal structure of Y2[MoO4]3 was solved at room temperature in the orthorhombic space group Pba2 (a = 1030.21(3), b = 1032.41(3), c = 1057.25(3) pm, Z = 4). In the unit cell, three discrete ortho-oxomolybdate(VI) units [MoO4]2− and two Y3+ cations, both with CN = 7 featuring a monocapped trigonal-prismatic oxygen environment, can be distinguished. Y2[MoO4]2[Mo2O7] crystallizes monoclinically in the space group P21/c (a = 681.85(2), b = 959.13(3), c = 1052.99(3) pm, β = 105.586(2)°) with two formula units per unit cell. In this compound the anionic environment …

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Refactoring The Silent Spectinabilin Gene Cluster Using A Plug-And-Play Scaffold, Zengyi Shao, Guodong Rao, Chun Li, Zhanar Abil, Yunzi Luo, Huimin Zhao Jan 2013

Refactoring The Silent Spectinabilin Gene Cluster Using A Plug-And-Play Scaffold, Zengyi Shao, Guodong Rao, Chun Li, Zhanar Abil, Yunzi Luo, Huimin Zhao

Zengyi Shao

Natural products (secondary metabolites) are a rich source of compounds with important biological activities. Eliciting pathway expression is always challenging but extremely important in natural product discovery because an individual pathway is tightly controlled through a unique regulation mechanism and hence often remains silent under the routine culturing conditions. To overcome the drawbacks of the traditional approaches that lack general applicability, we developed a simple synthetic biology approach that decouples pathway expression from complex native regulations. Briefly, the entire silent biosynthetic pathway is refactored using a plug-and-play scaffold and a set of heterologous promoters that are functional in a heterologous …

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Activation And Characterization Of A Cryptic Polycyclic Tetramate Macrolactam Biosynthetic Gene Cluster, Yunzi Luo, Hua Huang, Jing Liang, Meng Wang, Lu Lu, Zengyi Shao, Ryan E. Cobb, Huimin Zhao Jan 2013

Activation And Characterization Of A Cryptic Polycyclic Tetramate Macrolactam Biosynthetic Gene Cluster, Yunzi Luo, Hua Huang, Jing Liang, Meng Wang, Lu Lu, Zengyi Shao, Ryan E. Cobb, Huimin Zhao

Zengyi Shao

Polycyclic tetramate macrolactams (PTMs) are a widely distributed class of natural products with important biological activities. However, many of these PTMs have not been characterized. Here we apply a plug-and-play synthetic biology strategy to activate a cryptic PTM biosynthetic gene cluster SGR810-815 from Streptomyces griseus and discover three new PTMs. This gene cluster is highly conserved in phylogenetically diverse bacterial strains and contains an unusual hybrid polyketide synthase-nonribosomal peptide synthetase, which resembles iterative polyketide synthases known in fungi. To further characterize this gene cluster, we use the same synthetic biology approach to create a series of gene deletion constructs and …

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Structural Basis For Enzyme I Inhibition By Α-Ketoglutarate, Vincenzo Venditti, Rodolfo Ghirlando, G. Marius Clore Jan 2013

Structural Basis For Enzyme I Inhibition By Α-Ketoglutarate, Vincenzo Venditti, Rodolfo Ghirlando, G. Marius Clore

Vincenzo Venditti

Creating new bacterial strains in which carbon and nitrogen metabolism are uncoupled is potentially very useful for optimizing yields of microbial produced chemicals from renewable carbon sources. However, the mechanisms that balance carbon and nitrogen consumption in bacteria are poorly understood. Recently, α-ketoglutarate (αKG), the carbon substrate for ammonia assimilation, has been observed to inhibit Escherichia coli enzyme I (EI), the first component of the bacterial phosphotransferase system (PTS), thereby providing a direct biochemical link between central carbon and nitrogen metabolism. Here we investigate the EI-αKG interaction by NMR and enzymatic assays. We show that αKG binds with a KD …

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Structure, Dynamics And Biophysics Of The Cytoplasmic Protein–Protein Complexes Of The Bacterial Phosphoenolpyruvate: Sugar Phosphotransferase System, Vincenzo Venditti Jan 2013

Structure, Dynamics And Biophysics Of The Cytoplasmic Protein–Protein Complexes Of The Bacterial Phosphoenolpyruvate: Sugar Phosphotransferase System, Vincenzo Venditti

Vincenzo Venditti

The bacterial phosphotransferase system (PTS) couples phosphoryl transfer, via a series of bimolecular protein–protein interactions, to sugar transport across the membrane. The multitude of complexes in the PTS provides a paradigm for studying protein interactions, and for understanding how the same binding surface can specifically recognize a diverse array of targets. Fifteen years of work aimed at solving the solution structures of all soluble protein–protein complexes of the PTS has served as a test bed for developing NMR and integrated hybrid approaches to study larger complexes in solution and to probe transient, spectroscopically invisible states, including encounter complexes. We review …

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Improving Coalition Planning By Making Plans Alive, Jitu Patel, Michael C. Dorneich, David Mott, Ali Bahrami, Cheryl Giammanco Jan 2013

Improving Coalition Planning By Making Plans Alive, Jitu Patel, Michael C. Dorneich, David Mott, Ali Bahrami, Cheryl Giammanco

Michael C. Dorneich

The Collaborative Planning Model (CPM) supports human planners in managing planning information and facilitating automated reasoning. It aims to make plans 'alive' by digitizing planning concepts to facilitate their dynamic use, modification, dissemination, and reuse.

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Empirical Data And Regression Analysis For Estimation Of Infrastructure Resilience With Application To Electric Power Outages, Cameron A. Mackenzie, Kash Barker Jan 2013

Empirical Data And Regression Analysis For Estimation Of Infrastructure Resilience With Application To Electric Power Outages, Cameron A. Mackenzie, Kash Barker

Cameron A. MacKenzie

Recent natural disasters have highlighted the need for increased planning for disruptive events. Forecasting damage and time that a system will be inoperable is important for disruption planning. The resilience of critical infrastructure systems, or their ability to recover quickly from a disruption, can mitigate adverse consequences of the disruption. This paper quantifies the resilience of a critical infrastructure sector through the dynamic inoperability input-output model (DIIM). The DIIM, which describes how inoperability propagates through a set of interdependent industry and infrastructure sectors following a disruptive event, includes a resilience parameter that has not yet been adequately assessed. This paper …

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Abraham Model Correlations For Predicting Gas-To-Liquid Partition Coefficients And Activity Coefficients Of Organic Solutes Dissolved In 1-(2-Methoxyethyl)-1- Methylpyrrolidinium Tris(Pentafluoroethyl)Trifluorophosphate, Rui Jiang, Jared L. Anderson, Timothy W. Stephens, William E. Acree Jr., Micael H. Abraham Jan 2013

Abraham Model Correlations For Predicting Gas-To-Liquid Partition Coefficients And Activity Coefficients Of Organic Solutes Dissolved In 1-(2-Methoxyethyl)-1- Methylpyrrolidinium Tris(Pentafluoroethyl)Trifluorophosphate, Rui Jiang, Jared L. Anderson, Timothy W. Stephens, William E. Acree Jr., Micael H. Abraham

Jared L. Anderson

Chromatographic retention factors were measured for 45 different organic solutes of varying polarity and hydrogen-bonding capability on an anhydrous 1-(2-methoxyethyl)-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate, ([MeoeMPyrr]+ [FAP]– ), stationary phase at both 323 K and 353 K. The experimental retention factor data were combined with recently published thermodynamic data for solutes dissolved in ([MeoeMPyrr]+ [FAP]– ) to give the corresponding gas-to-liquid partition coefficients (log K). The water-to-anhydrous ([MeoeMPyrr]+ [FAP]– ) partition coefficients (log P) were also calculated using published gas-to-water partition coefficient data for the solutes studied. The derived partition coefficients were analyzed in accordance with the Abraham model. The Abraham model expressions that …

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Emerging Technologies For Non-Invasive Quantification Of Physiological Oxygen Transport In Plants, P. Chaturvedi, M. Taguchi, S. L. Burrs, B. A. Hauser, W.W. A.W. Salim, Jonathan C. Claussen, E. S. Mclamore Jan 2013

Emerging Technologies For Non-Invasive Quantification Of Physiological Oxygen Transport In Plants, P. Chaturvedi, M. Taguchi, S. L. Burrs, B. A. Hauser, W.W. A.W. Salim, Jonathan C. Claussen, E. S. Mclamore

Jonathan C. Claussen

Oxygen plays a critical role in plant metabolism, stress response/signaling, and adaptation to environmental changes (Lambers and Colmer, Plant Soil 274:7-15, 2005; Pitzschke et al., Antioxid Redox Signal 8:1757-1764, 2006; Van Breusegem et al., Plant Sci 161:405-414, 2001). Reactive oxygen species (ROS), by-products of various metabolic pathways in which oxygen is a key molecule, are produced during adaptation responses to environmental stress. While much is known about plant adaptation to stress (e.g., detoxifying enzymes, antioxidant production), the link between ROS metabolism, O2 transport, and stress response mechanisms is unknown. Thus, non-invasive technologies for measuring O2 are critical for understanding the …

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New Generation Of Ensemble-Decision Aliquot Ranking Based On Simplified Microfluidic Components For Large-Capacity Trapping Of Circulating Tumor Cells, Mengxia Zhao, Wyatt C. Nelson, Bingchuan Wei, Perry G. Schiro, Bejan M. Hakimi, Eleanor S. Johnson, Robbyn K. Anand, Grace S. Gyurkey, Lisa M. White, Samuel H. Whiting, Andrew L. Coveler, Daniel T. Chiu Jan 2013

New Generation Of Ensemble-Decision Aliquot Ranking Based On Simplified Microfluidic Components For Large-Capacity Trapping Of Circulating Tumor Cells, Mengxia Zhao, Wyatt C. Nelson, Bingchuan Wei, Perry G. Schiro, Bejan M. Hakimi, Eleanor S. Johnson, Robbyn K. Anand, Grace S. Gyurkey, Lisa M. White, Samuel H. Whiting, Andrew L. Coveler, Daniel T. Chiu

Robbyn Anand

Ensemble-decision aliquot ranking (eDAR) is a sensitive and high-throughput method to analyze circulating tumor cells (CTCs) from peripheral blood. Here, we report the next generation of eDAR, where we designed and optimized a new hydrodynamic switching scheme for the active sorting step in eDAR, which provided fast cell sorting with an improved reproducibility and stability. The microfluidic chip was also simplified by incorporating a functional area for subsequent purification using microslits fabricated by standard lithography method. Using the reported second generation of eDAR, we were able to analyze 1 mL of whole-blood samples in 12.5 min, with a 95% recovery …

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Interface-Assisted Ionothermal Synthesis, Phase Tuning, Surface Modification And Bioapplication Of Ln3+-Doped Nagdf4 Nanocrystals, Qiang Ju, Paul S. Campbell, Anja V. Mudring Jan 2013

Interface-Assisted Ionothermal Synthesis, Phase Tuning, Surface Modification And Bioapplication Of Ln3+-Doped Nagdf4 Nanocrystals, Qiang Ju, Paul S. Campbell, Anja V. Mudring

Anja V. Mudring

Phase-selective synthesis of trivalent lanthanide-doped NaGdF4 nanocrystals, capped by ionic liquid cations bearing long alkyl chains, succeeded via a one-step interface-assisted ionothermal route. Owing to the existence of an interface formed between hydrophobic ionic liquids and ethylene glycol, selectively either pure cubic or hexagonal phase NaGdF4 could be obtained by changing the amount of the added surfactant, polyethyleneimine. By doping various trivalent lanthanide cations, multicolor emissions under excitation by a single wavelength could be achieved. The nanocrystals can be surface derivatized by an amphiphilic polymer and endowed with functional groups that allow the particles to not only be dispersed in …

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Phase And Morphology Selective Interface-Assisted Synthesis Of Highly Luminescent Ln3+-Doped Nagdf4 Nanorods, Anja V. Mudring, Qiang Ju Jan 2013

Phase And Morphology Selective Interface-Assisted Synthesis Of Highly Luminescent Ln3+-Doped Nagdf4 Nanorods, Anja V. Mudring, Qiang Ju

Anja V. Mudring

Making use of the multifunctional properties of ionic liquids by employing them as a fluoride resource and hydrophilic phase, we have grown small, monodisperse, highly luminescent Ln3+-doped NaGdF4 nanorods at the interface between octadecene and the reactive ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate. The obtained nanocrystals could further be endowed with functional groups and rendered water dispersible, which allows them to be used for biodetection.

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White-Light-Emitting Single Phosphors Via Triply Doped Laf3 Nanoparticles, Chantal Lorbeer, Anja V. Mudring Jan 2013

White-Light-Emitting Single Phosphors Via Triply Doped Laf3 Nanoparticles, Chantal Lorbeer, Anja V. Mudring

Anja V. Mudring

The production of high-quality phosphors for white-emitting applications is an important goal for the settlement of light-emitting diodes (LEDs) in the market and households. Single phosphors directly yielding white emission are advantageous in comparison to a mixture of individual red, green, and blue phosphors as these are hampered by reabsorption of the blue light. Here, a combined approach to uniform, nanoscale particles as single-white-emitting phosphor is realized via an ionic-liquid-based synthesis. LaF3 particles codoped with various amounts of Tm3+, Tb3+, and Eu3+ were synthesized, and their structural, morphological, and optical properties were studied. Small particles with a mean size of …

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On The Mesophase Formation Of 1,3-Dialkylimidazolium Ionic Liquids, Mei Yang, Bert Mallick, Anja V. Mudring Jan 2013

On The Mesophase Formation Of 1,3-Dialkylimidazolium Ionic Liquids, Mei Yang, Bert Mallick, Anja V. Mudring

Anja V. Mudring

A series of seven different 1,3-dialkylimidazolium-based ion-pair salts with the same molecular weight and size but different symmetries was synthesized. For all salts, bromide was chosen as the counterion, giving the series ([CnIMCm][Br]), where IM = imidazolium and Cn and Cm are varying N-alkyl substituents with n + m = 13. Thus, the effect of symmetry on the physicochemical properties, such as thermal transitions, densities and viscosities and particularly mesophase formation, is investigated herein. All salts are fully characterized by NMR spectroscopy and mass spectrometry, and their physicochemical properties such as thermal transitions, densities, and viscosities are reported. Single crystal …

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