bluuebunny/crossref_metadata_2025 huggingface dataset:
Considering organic mechanisms and the optimization of current flow in an electrochemical oxidative condensation reaction
Authors: Rensing Derek T. , Nguyen Bichlien H. , Moeller Kevin D.
Published: July 2016

Careful consideration of the chemical mechanism for an oxidative condensation reaction led to improved current flow for the electrolysis.
Preparation and preliminary application of 5-HMF@SiO2 micro-particles
Authors: Wang Cheng , He Huaizhen , Lin Yuanyuan , Huang Limin , Sun Meng , Zhang Tao , He Langchong
Published: July 2016

We report an organic–inorganic hybrid composite of surface-modified silica gel with 5-hydroxymethylfurfural, which provided a new promising stationary phase for protein separation.
Eu3+-doped ionogel-functionalized carbon dot monoliths with bright white photoluminescence
Authors: Dai Bin , Deng Degang , Yu Hua , Lei Lei , Li Yinyan , Li Chenxia , Xu Shiqing
Published: July 2016

Eu3+-doped ionogel-functionalized carbon dot monoliths provide new potential for applications of carbon nanoparticles in optoelectronic devices.
Multifunctional polymer nanoparticles: ultra bright near-infrared fluorescence and strong magnetization and their biological applications
Authors: Yan Lulin , Zhang Yan , Ji Guang , Ma Lian , Chen Jinlong , Xu Bin , Tian Wenjing
Published: July 2016

Magnetic fluorescent multifunctional polymer NPs Fe3O4/DPPBPA@F-127 and their application in MRI and NIR imaging.
Synthesis, antimicrobial, anti-cancer and molecular docking of two novel hitherto unreported thiophenes
Authors: Mabkhot Yahia N. , Kheder Nabila Abdelshafy , Barakat Assem , Choudhary Muhammad I. , Yousuf Sammer , Frey Wolfgang
Published: July 2016

One pot synthesis of two novel hitherto unreported thiophenes was achieved by a facile and selective synthetic method.
Effect of few-layer graphene films as electrodes on the electrical properties of ferroelectric capacitors
Authors: Han Hong Jing , Chen Yan Na , Wang Zhan Jie
Published: July 2016

An FLG/PZT/Pt capacitor exhibits comparable polarization compared with a Pt/PZT/Pt capacitor but the magnitude of leakage current density for the FLG/PZT/Pt capacitor is largely decreased due to the van der Waals gap at the FLG/PZT interface.
A polybenzimidazole/graphite oxide based three layer membrane for intermediate temperature polymer electrolyte membrane fuel cells
Authors: Deng Yuming , Wang Gang , Fei Ming Ming , Huang Xin , Cheng Jigui , Liu Xiaoteng , Xing Lei , Scott Keith , Xu Chenxi
Published: July 2016

PBI/GO/PBI composite membrane exhibited acceptable proton conductivity and fuel cell performance at 150 °C. The graphite oxide as proton conductor layer enhanced the mechanical strength and reduced the swelling ratio of electrolyte at intermediate temperature.
Ultrathin nickel sulfide nano-flames as an electrode for high performance supercapacitor; comparison of symmetric FSS-SCs and electrochemical SCs device
Authors: Patil A. M. , Lokhande V. C. , Lokhande A. C. , Chodankar N. R. , Ji T. , Kim J. H. , Lokhande C. D.
Published: July 2016

(a) The schematic for fabrication of the symmetric FSS-SCs device, (b) demonstration of FSS-SCs device with the glow of a red LED and (c) the performance comparison of symmetric FSS-SCs and electrochemical SCs device.
Transverse axis morphological control for tailored gold nanorod (GNR) synthesis
Authors: Boyne D. A. , Chipara A. C. , Griep M. H.
Published: July 2016

Selective radial growth of gold nanorods with tailored optical absorption control between 550–850 nm.
Molecular dynamic simulations of pressure-driven water transport through polyamide nanofiltration membranes at different membrane densities
Authors: Wang Luying , Dumont Randall S. , Dickson James M.
Published: July 2016

The amorphous aromatic polyamide membranes with different membrane densities were modeled to study the porous structure of free-volume pores and the pressure-driven water transport by using molecular dynamics simulations.
In situ photoacoustic spectroscopic analysis on photocatalytic decolorization of methylene blue over titanium(iv) oxide particles
Authors: Murakami Naoya , Maruno Hirotaka
Published: July 2016

Photoabsorption of an aqueous suspension containing methylene blue (MB) dye and titanium(iv) oxide (TiO2) powder was evaluated using photoacoustic spectroscopy (PAS), and the photocatalytic decolorization of MB over TiO2 was observed using PAS.
Synthesis of 2-hydroxy-3-alkyl-2-phenyl-2,3-dihydroquinazolin-4(1H)-one via molybdenum hexacarbonyl mediated CO gas- and ligand free carbonylative reactions
Authors: Subba Rao J. , Venkateswara Rao A. , Krishna T. , Murthy V. N. , Rajesh J. , Raghunadh A.
Published: July 2016

Carbon monoxide gas and ligand-free condition were developed for the synthesis of 2-hydroxy-3-alkyl-2-phenyl-2,3-dihydroquinazolin-4(1H)-one via catalytic carbonylation with Mo(CO)6 as an efficient carbonylating agent for the novel MCR reaction.
Citrus hystrix-derived 3,7-dimethyloct-6-enal and 3,7-dimethyloct-6-enyl acetate ameliorate acetylcholine deficits
Authors: Sammi Shreesh Raj , Mishra Durga Prasad , Trivedi Shalini , Smita Shachi S. , Nagar Abhishek , Tandon Sudeep , Pandey Rakesh
Published: July 2016

Cholinergic neurotransmission is an affliction in a plethora of neurodegenerative disorders such as Alzheimer’s, Huntington’s and Parkinson’s diseases and some psychiatric disorders like schizophrenia.
Novel microlens arrays with embedded Al2O3nanoparticles for enhancing efficiency and stability of flexible polymer light-emitting diodes
Authors: Kim Young Yun , Park Jung Jin , Ye Seong Ji , Hyun Woo Jin , Im Hyeon-Gyun , Bae Byeong-Soo , Park O Ok
Published: July 2016

Microlens arrays were newly fabricated with silica hybrid sol and Al2O3nanoparticles, to enhance efficiency and stability of polymer light-emitting diodes, as well as to minimize changes in optical properties.
Reversible modulation of the activity of thiourea catalysts with anions: a simple approach to switchable asymmetric catalysis
Authors: Foli Giacomo , D'Elia Cecilia Sasso , Fochi Mariafrancesca , Bernardi Luca
Published: July 2016

A simple and straightforward approach to switchable asymmetric catalysis is presented, based on the interactions of thiourea catalysts with anions.
Heat transfer performance of water-based tetrahydrofurfuryl polyethylene glycol-treated graphene nanoplatelet nanofluids
Authors: Arzani Hamed Khajeh , Amiri Ahmad , Kazi S. N. , Badarudin A. , Chew B. T.
Published: July 2016

In order to improve the colloidal stability of graphene nanoplatelets (GNPs) in aqueous media, GNPs were first functionalized with tetrahydrofurfuryl polyethylene glycol in a quick electrophilic addition reaction method.
Quaternized N-chloramine coated magnetic nanoparticles: a trifecta of superior antibacterial activity, minimal residual toxicity and rapid site removal
Authors: Rahma Hakim , Nickel Rachel , Skoropata Elizabeth , Wroczynskyj Yaroslav , Rutley Christopher , Manna Palash K. , Hsiao Ching Hung , Ouyang Hao , van Lierop Johan , Liu Song
Published: July 2016

Applying nanoscience and nanotechnology to potentially allow the safe use of potent broad-spectrum biocides on topical wounds.
The effect of incubation conditions on the hemolytic properties of unmodified graphene oxide with various concentrations
Authors: Wang Yang , Zhang Baomei , Zhai Guangxi
Published: July 2016

The hemolytic properties of graphene oxide (GO) were evaluated from the novel view of the incubation conditions.
Surface carbon species formation from ethylene decomposition on Pd(100): a first-principles-based kinetic Monte Carlo study
Authors: Huang Yanping , Dong Xiuqin , Yu Yingzhe
Published: July 2016

Based on the activation barriers and reaction energies from periodic density functional calculations, we conducted kinetic Monte Carlo (kMC) simulations of surface carbon species formation from ethylene decomposition on a Pd(100) surface.
A study of CO2/CO separation by sub-micron b-oriented MFI membranes
Authors: Korelskiy D. , Grahn M. , Ye P. , Zhou M. , Hedlund J.
Published: July 2016

CO2/CO separation is challenging. Here we report high-flux MFI membranes for effective CO2removal from CO by selective CO2adsorption in the MFI. On top, diffusional coupling at high CO2loadings reduce the CO transport favouring CO2/CO selectivity.
Tantalum nitride films integrated with transparent conductive oxide substrates via atomic layer deposition for photoelectrochemical water splitting
Authors: Hajibabaei Hamed , Zandi Omid , Hamann Thomas W.
Published: July 2016

The first example of tantalum nitride electrodes on transparent conductive oxide substrates, which enables solar water splitting, is presented.
Organised chaos: entropy in hybrid inorganic–organic systems and other materials
Authors: Butler Keith T. , Walsh Aron , Cheetham Anthony K. , Kieslich Gregor
Published: July 2016

Entropy is one of the fundamental quantities which links emerging research areas like flexibility and defect engineering in inorganic–organic hybrid materials. Here, we highlight the role of entropy in the past and discuss how computational methods can help us to understand entropic effects in inorganic–organic hybrid materials in the future.
Self-powered fluorescence display devices based on a fast self-charging/recharging battery (Mg/Prussian blue)
Authors: Zhang Hui , Yu You , Zhang Lingling , Zhai Yiwen , Dong Shaojun
Published: July 2016

Here we designed and fabricated a self-powered fluorescence display device based on a fast-charging/recharging battery, composed of a Prussian blue (PB) cathode and a magnesium metal anode with a high theoretical redox potential difference.
Permanently grafted icephobic nanocomposites with high abrasion resistance
Authors: Gao Jing , Martin Andrew , Yatvin Jeremy , White Evan , Locklin Jason
Published: July 2016

In this work, a series of copolymer/silica nanocomposites are investigated that exhibit excellent anti-icing behavior and can be covalently grafted to any substrate containing C–H bonds with high durability.
Multi-shelled MgCo2O4 hollow microspheres as anodes for lithium ion batteries
Authors: Shin Haeun , Lee Wan-Jin
Published: July 2016

Multi-shelled MgCo2O4 hollow microspheres (MCOs) with a spinel structure as an anode material for lithium ion batteries are prepared through a solvothermal process using colloidal carbon spheres as a template, followed by a calcination process in air.
Degradable cellulose acetate/poly-l-lactic acid/halloysite nanotube composite nanofiber membranes with outstanding performance for gel polymer electrolytes
Authors: Zhu Ming , Lan Jinle , Tan Chunyu , Sui Gang , Yang Xiaoping
Published: July 2016

The biodegraded cellulose acetate (CA)/poly-l-lactic acid (PLLA)/halloysite nanotube composite nanofiber membranes were fabricated for the preparation of gel polymer electrolytes (GPEs) used in lithium-ion batteries.
Photo-antimicrobial polymeric films releasing nitric oxide with fluorescence reporting under visible light
Authors: Marino Nino , Perez-Lloret Marta , Blanco Anna R. , Venuta Alessandro , Quaglia Fabiana , Sortino Salvatore
Published: July 2016

A novel molecular hybrid has been embedded in poly(lactic-co-glycolic acid) to give an antibacterial film photogenerating NO with a concomitant fluorescent reporter.
Correction: Bioactive SiO2@Ru nanoparticles for osteogenic differentiation of mesenchymal stem cells via activation of Akt signaling pathways
Authors: Liu Ying , Huang Na , Yu Yunfei , Zheng Chuping , Deng Ning , Liu Jie
Published: July 2016

Correction for ‘Bioactive SiO2@Ru nanoparticles for osteogenic differentiation of mesenchymal stem cells via activation of Akt signaling pathways’ by Ying Liu et al., J. Mater. Chem. B, 2016, DOI: 10.1039/c5tb01898f.
The Effect of Noise on Relationships Between Speech Intelligibility and Self-Reported Communication Measures in Tracheoesophageal Speakers
Authors: Eadie Tanya L. , Otero Devon Sawin , Bolt Susan , Kapsner-Smith Mara , Sullivan Jessica R.
Published: July 2016

Purpose

The purpose of this study was to examine how sentence intelligibility relates to self-reported communication in tracheoesophageal speakers when speech intelligibility is measured in quiet and noise.

Method

Twenty-four tracheoesophageal speakers who were at least 1 year postlaryngectomy provided audio recordings of 5 sentences from the Sentence Intelligibility Test. Speakers also completed self-reported measures of communication—the Voice Handicap Index-10 and the Communicative Participation Item Bank short form. Speech recordings were presented to 2 groups of inexperienced listeners who heard sentences in quiet or noise. Listeners transcribed the sentences to yield speech intelligibility scores.

Results

Very weak relationships were found between intelligibility in quiet and measures of voice handicap and communicative participation. Slightly stronger, but still weak and nonsignificant, relationships were observed between measures of intelligibility in noise and both self-reported measures. However, 12 speakers who were more than 65% intelligible in noise showed strong and statistically significant relationships with both self-reported measures (
R
2
= .76–.79).

Conclusions

Speech intelligibility in quiet is a weak predictor of self-reported communication measures in tracheoesophageal speakers. Speech intelligibility in noise may be a better metric of self-reported communicative function for speakers who demonstrate higher speech intelligibility in noise.
A Gift for the New Year
Authors: Minghetti Nancy
Published: July 2016

Under a new resolution, ASHA will increase its annual contribution to the American Speech-Language-Hearing Foundation.
From the President: Working Early-Intervention Magic in Community Settings
Authors: Prelock Patty
Published: July 2016

Children with disabilities benefit most when professionals let families lead the way.
In the Limelight: The Dudes Abide
Authors: Rowden-Racette Kellie
Published: July 2016

When you're ready to see the edgy side of speech-language pathology, let these SLPs be your tour guides.
In the Limelight: Tuning In
Authors: Rowden-Racette Kellie
Published: July 2016

Cochlear implants helped give audiologist Sandy Mintz optimism she never thought she had.
Listen Up, Class
Authors: Smiley Donna F.
Published: July 2016

How to bridge the gap between the audiology clinic and the classroom? Educational audiologist Donna Fisher Smiley led a recent online chat tackling that question, and the Leader was there.
Policy Analysis: The Maze of Manual Medical Review
Authors: Nanof Tim , Satterfield Lisa
Published: July 2016

Medicare officials clarify concerns and offer to review questionable denials of therapy claims.
Policy Analysis: Federal Report Targets 'Incident To' Billing
Authors: Satterfield Lisa
Published: July 2016

Audiologists may be audited if they bill Medicare hearing and balance diagnostic services under a physician's name and identification.
Policy Analysis: Proposed Medicare Rules Cut Fees, Alter Reporting Requirements
Authors: Satterfield Lisa , Swanson Neela
Published: July 2016

SLPs and audiologists could see lower reimbursements, even with congressional intervention.
Student's Say: Why Take 18 Extra Graduate School Credit Hours?
Authors: Peck Margo , Lamb Holly
Published: July 2016

Graduate speech-language pathology students took on an extra load for what they admit were self-serving reasons, but were surprised by the results.
Student's Say: NSSLHA Day Celebrates 10 Years
Authors: Didier Jenna
Published: July 2016

Student events at the 2013 convention have a new name—The NSSLHA Experience at the ASHA Convention—and a new centralized location. Check out what's in store.
A United International Voice for Aphasia
Authors: Hinckley Jacqueline , Worrall Linda , Ganzfried Ellayne , Simmons-Mackie Nina
Published: July 2016

With aphasia on the rise worldwide, a new group will unite international efforts and drive change.
Suture or Stapling Are Superior in Comparison to Bipolar Sealing for Closing the Bronchi
Authors: Waubke Katharina , Pehl Anika , Steinfeldt Thorsten , Bartsch Detlef , Kirschbaum Andreas
Published: July 2016

Background Every anatomical lung resection requires the airtight closure of at least one bronchus. In current clinical practice, these bronchi are sealed with sutures or staplers. This study investigated in an ex vivo pig model whether a new bipolar sealing device MARSEAL (KLS Martin, Tuttlingen, Germany) could be an alternative for this purpose.

Methods Complete bronchial trees were prepared free from pig heart–lung blocks that were removed at a slaughterhouse. These preparations were taken to the laboratory, and main, lobar, and segmental bronchi were closed using sutures, staples, or bipolar sealing. Each trachea was then intubated and connected to a ventilating device. The initial airtight closure of the bronchus was first tested with lung-protective ventilation. After 15 minutes of ventilation, the inspiratory ventilation pressure was slowly increased and the burst pressure (in mbar) was recorded. Each group included 12 bronchus closures. Group mean burst pressures were compared using a nonparametric test (Mann–Whitney U test). The significance level was p < 0.05.

Results The main bronchi closed both stapler magazines or sutures were all initially airtight during ventilation. The mean burst pressure was 60 ± 0 mbar for staplers and 57.92 ± 5.8 mbar for sutures. In contrast, 50% of main bronchi sealed with MARSEAL devices (5 or 10 mm) leaked air from the beginning. This was also noted in all lobar bronchi sealed with the MARSEAL 5-mm device and 80% of those sealed with the MARSEAL 10-mm device. The mean burst pressure of initially airtight lobar bronchi was 12.7 ± 7.25 mbar. In contrast, all segmental bronchi (mean width: 1.6 cm) were airtight when ventilated. Mean burst pressure was 14.64 ± 9.1 mbar with the MARSEAL 5-mm device and 29.64 ± 21.3 mbar with the MARSEAL 10-mm device. Histological investigation of the preparations (with hematoxylin and eosin staining) showed intact cartilaginous structures that were largely unaffected by bipolar coagulation. The airtight sealing of the segmental bronchi resulted from fusion of the peribronchial tissue and not the cartilage.

Conclusion Bipolar sealing is an inappropriate tool for the closure of the bronchi in comparison to suture or stapling.
Numerical studies of independent control of electron density and gas temperature via nonlinear coupling in dual-frequency atmospheric pressure dielectric barrier discharge plasmas
Authors: Zhang Z. L. , Nie Q. Y. , Wang Z. B. , Gao X. T. , Kong F. R. , Sun Y. F. , Jiang B. H.
Published: July 2016

Dielectric barrier discharges (DBDs) provide a promising technology of generating non-equilibrium cold plasmas in atmospheric pressure gases. For both application-focused and fundamental studies, it is important to explore the strategy and the mechanism for enabling effective independent tuning of key plasma parameters in a DBD system. In this paper, we report numerical studies of effects of dual-frequency excitation on atmospheric DBDs, and modulation as well as separate tuning mechanism, with emphasis on dual-frequency coupling to the key plasma parameters and discharge evolution. With an appropriately applied low frequency to the original high frequency, the numerical calculation demonstrates that a strong nonlinear coupling between two frequencies governs the process of ionization and energy deposition into plasma, and thus raises the electron density significantly (e.g., three times in this case) in comparisons with a single frequency driven DBD system. Nevertheless, the gas temperature, which is mainly determined by the high frequency discharge, barely changes. This method then enables a possible approach of controlling both averaged electron density and gas temperature independently.
Investigation of full and partial ground effects on a flapping foil hovering above a finite-sized platform
Authors: Wang Lu , Yeung Ronald W.
Published: July 2016

The full and partial ground effects on the lift generation of a flapping airfoil in normal hovering mode are investigated numerically using the discrete vortex method in two dimensions. To achieve full ground effect, the airfoil of chord c is made to hover above the center of a finite-sized platform of length 10c. We have observed the force-enhancement, force-reduction, and force-recovery regimes at low, medium, and high ground clearances in line with the existing literature. This paper puts special focus on partial ground effect when the airfoil is hovering near the edge of the platform. Lift-modifying mechanisms not previously observed under full ground effect have been discovered. When stroke reversal occurs near the edge of the platform, a relatively stationary strong vortex may form above the platform edge. This strong vortex can either increase or decrease the instantaneous lift force on the airfoil depending on the position of the airfoil relative to the platform edge. Also, the platform edge may lead to the formation of an additional vortex pair which increases the instantaneous lift force as the airfoil sweeps past the edge under suitable conditions. Lastly, the platform edge can lead to the formation of a reverse von Kármán vortex street that extends well below the stroke plane under suitable geometric arrangements.
Numerical and experimental investigation of natural flow-induced vibrations of flexible hydrofoils
Authors: Chae Eun Jung , Akcabay Deniz Tolga , Lelong Alexandra , Astolfi Jacques Andre , Young Yin Lu
Published: July 2016

The objective of this work is to present combined numerical and experimental studies of natural flow-induced vibrations of flexible hydrofoils. The focus is on identifying the dependence of the foil’s vibration frequencies and damping characteristics on the inflow velocity, angle of attack, and solid-to-fluid added mass ratio. Experimental results are shown for a cantilevered polyacetate (POM) hydrofoil tested in the cavitation tunnel at the French Naval Academy Research Institute (IRENav). The foil is observed to primarily behave as a chordwise rigid body and undergoes spanwise bending and twisting deformations, and the flow is observed to be effectively two-dimensional (2D) because of the strong lift retention at the free tip caused by a small gap with a thickness less than the wall boundary layer. Hence, the viscous fluid-structure interaction (FSI) model is formulated by coupling a 2D unsteady Reynolds-averaged Navier-Stokes (URANS) model with a two degree-of-freedom (2-DOF) model representing the spanwise tip bending and twisting deformations. Good agreements were observed between viscous FSI predictions and experimental measurements of natural flow-induced vibrations in fully turbulent and attached flow conditions. The foil vibrations were found to be dominated by the natural frequencies in absence of large scale vortex shedding due to flow separation. The natural frequencies and fluid damping coefficients were found to vary with velocity, angle of attack, and solid-to-fluid added mass ratio. In addition, the numerical results showed that the in-water to in-air natural frequency ratios decreased rapidly, and the fluid damping coefficients increased rapidly, as the solid-to-fluid added mass ratio decreases. Uncoupled mode (UM) linear potential theory was found to significantly over-predict the fluid damping for cases of lightweight flexible hydrofoils, and this over-prediction increased with higher velocity and lower solid-to-fluid added mass ratio.
Extra dissipation and flow uniformization due to elastic instabilities of shear-thinning polymer solutions in model porous media
Authors: Machado Anaïs , Bodiguel Hugues , Beaumont Julien , Clisson Gérald , Colin Annie
Published: July 2016

We study flows of hydrolized polyacrylamide solutions in two dimensional porous media made using microfluidics, for which elastic effects are dominant. We focus on semi-dilute solutions (0.1%–0.4%) which exhibit a strong shear thinning behavior. We systematically measure the pressure drop and find that the effective permeability is dramatically higher than predicted when the Weissenberg number is greater than about 10. Observations of the streamlines of the flow reveal that this effect coincides with the onset of elastic instabilities. Moreover, and importantly for applications, we show using local measurements that the mean flow is modified: it appears to be more uniform at high Weissenberg number than for Newtonian fluids. These observations are compared and discussed using pore network simulations, which account for the effect of disorder and shear thinning on the flow properties.
Analytical solution for the lubrication force between two spheres in a bi-viscous fluid
Authors: Vázquez-Quesada A. , Ellero M.
Published: July 2016

An analytical solution for the calculation of the normal lubrication force acting between two moving spheres embedded in a shear-thinning fluid represented by a bi-viscous model is provided. The resulting force between the suspended spheres exhibits a consistent transition between the Newtonian constant-viscosity limits and it reduces to the well-known standard Newtonian lubrication theory for viscosity-ratio approaching one. Effects of several physical parameters of the theory are analyzed under relevant physical conditions, i.e., for a prototypical case of two non-colloidal spheres immersed in a non-Newtonian fluid with rheology parameterized by a bi-viscosity model. Topological results for high/low-viscosity regions in the gap between spheres are also analyzed in detail showing a rich phenomenology. The presented model enables the extension of lubrication dynamics for suspensions interacting with non-Newtonian matrices and provides a clean theoretical framework for new numerical computations of flow of dense complex particulate systems.
Electrostatics of polymer translocation events in electrolyte solutions
Authors: Buyukdagli Sahin , Ala-Nissila T.
Published: July 2016

We develop an analytical theory that accounts for the image and surface charge interactions between a charged dielectric membrane and a DNA molecule translocating through the membrane. Translocation events through neutral carbon-based membranes are driven by a competition between the repulsive DNA-image-charge interactions and the attractive coupling between the DNA segments on the trans and the cis sides of the membrane. The latter effect is induced by the reduction of the coupling by the dielectric membrane. In strong salt solutions where the repulsive image-charge effects dominate the attractive trans-cis coupling, the DNA molecule encounters a translocation barrier of ≈10 kBT. In dilute electrolytes, the trans-cis coupling takes over image-charge forces and the membrane becomes a metastable attraction point that can trap translocating polymers over long time intervals. This mechanism can be used in translocation experiments in order to control DNA motion by tuning the salt concentration of the solution.
Stiffness parameter of brush-like polymers with rod-like side chains
Authors: Nakamura Yo
Published: July 2016

The stiffness parameter λ−1 of brush-like polymers having rod-like side chains with the hard core potential was calculated. Side chains are, first, assumed to be connected with a free joint to the main chain. The free energy per molecule F was calculated invoking the single contact approximation in which only the interaction between two side chains is considered and the higher interactions are ignored. In the calculation, the contact is assumed to occur when the two side chains are in a plain and the condition for the angles between the side chain and the main chain to make a triangle by two side chains and the main chain was exactly taken into account. The change of F after bending the main chain with a certain curvature from the straight state was calculated to obtain λ−1. The resulting λ−1 came close to the experimental value for brush-like polymers with a poly(methacrylate) main chain and poly(hexylisocyanate) (PHIC) side chains if we add a constant as the intrinsic stiffness of the main chain, λ0−1, to it. By considering the potential function having a minimum when the angle between the side and main chains equals π/2, the data for brush-like polymers with a poly(styrene) main chain and PHIC side chains were also closely fitted by the theoretical values with an appropriate value of λ0−1 and the force constant of the angle.
Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions
Authors: Nikolaev A. V. , Lamoen D. , Partoens B.
Published: July 2016

In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the u̇l-component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets.
Microfluidic viscometers for shear rheology of complex fluids and biofluids
Authors: Gupta Siddhartha , Wang William S. , Vanapalli Siva A.
Published: July 2016

The rich diversity of man-made complex fluids and naturally occurring biofluids is opening up new opportunities for investigating their flow behavior and characterizing their rheological properties. Steady shear viscosity is undoubtedly the most widely characterized material property of these fluids. Although widely adopted, macroscale rheometers are limited by sample volumes, access to high shear rates, hydrodynamic instabilities, and interfacial artifacts. Currently, microfluidic devices are capable of handling low sample volumes, providing precision control of flow and channel geometry, enabling a high degree of multiplexing and automation, and integrating flow visualization and optical techniques. These intrinsic advantages of microfluidics have made it especially suitable for the steady shear rheology of complex fluids. In this paper, we review the use of microfluidics for conducting shear viscometry of complex fluids and biofluids with a focus on viscosity curves as a function of shear rate. We discuss the physical principles underlying different microfluidic viscometers, their unique features and limits of operation. This compilation of technological options will potentially serve in promoting the benefits of microfluidic viscometry along with evincing further interest and research in this area. We intend that this review will aid researchers handling and studying complex fluids in selecting and adopting microfluidic viscometers based on their needs. We conclude with challenges and future directions in microfluidic rheometry of complex fluids and biofluids.
Determining internal screening electric field of working polymer light emitting diodes
Authors: Kanemoto Katsuichi , Takahashi Takahiro , Hashimoto Hideki
Published: July 2016

This study provides a method of determining the internal electric field of polymer light emitting diodes (LEDs) in the working condition. The method employs Stark signals induced by triangular shaped pulse biases and enables estimates of the internal field in a broad voltage region. The internal field under forward bias is shown to be determined by the screening effect caused by injected carriers. Spatial distribution calculated for the LED suggests the presence of strong electric field formed by accumulated carriers near the electrodes. The proposed method is applicable to a variety of devices and can promote understanding of veiled roles of internal fields on device operation.
Multi-band asymmetric acoustic transmission in a bended waveguide with multiple mechanisms
Authors: Huang Yu-lei , Sun Hong-xiang , Xia Jian-ping , Yuan Shou-qi , Ding Xin-lei
Published: July 2016

We report the realization of a multi-band device of the asymmetric acoustic transmission by placing a phononic crystal inside a bended waveguide immersed in water, as determined both experimentally and numerically. The asymmetric acoustic transmission exists in three frequency bands below 500 kHz induced by multiple mechanisms. Besides the band gap of the phononic crystal, we also introduce the deaf mode and interaction between the phononic crystal and waveguide. More importantly, this asymmetric transmission can be systematically controlled by mechanically rotating the square rods of the phononic crystal. The device has the advantages of multiple band, broader bandwidth, and adjustable property, showing promising applications in ultrasonic devices.
Diffusion and recrystallization of B implanted in crystalline and pre-amorphized Ge in the presence of F
Authors: Hsu William , Kim Taegon , Benítez-Lara Alfredo , Chou Harry , Dolocan Andrei , Rai Amritesh , Josefina Arellano-Jiménez M. , Palard Marylene , José-Yacamán Miguel , Banerjee Sanjay K.
Published: July 2016

Although the diffusion control and dopant activation of Ge p-type junctions are straightforward when using B+ implantation, the use of the heavier BF2+ ions or even BF+ is still favored in terms of shallow junction formation and throughput—because implants can be done at higher energies, which can give higher beam currents and beam stability—and thus the understanding of the effect of F co-doping becomes important. In this work, we have investigated diffusion and end-of-range (EOR) defect formation for B+, BF+, and BF2+ implants in crystalline and pre-amorphized Ge, employing rapid thermal annealing at 600 °C and 800 °C for 10 s. It is demonstrated that the diffusion of B is strongly influenced by the temperature, the presence of F, and the depth of amorphous/crystalline interface. The B and F diffusion profiles suggest the formation of B–F complexes and enhanced diffusion by interaction with point defects. In addition, the strong chemical effect of F is found only for B in Ge, while such an effect is vanishingly small for samples implanted with F alone, or co-implanted with P and F, as evidenced by the high residual F concentration in the B-doped samples after annealing. After 600 °C annealing for 10 s, interstitial-induced compressive strain was still observed in the EOR region for the sample implanted with BF+, as measured by X-ray diffraction. Further analysis by cross-sectional transmission electron microscopy showed that the {311} interstitial clusters are the majority type of EOR defects. The impact of these {311} defects on the electrical performance of Ge p+/n junctions formed by BF+ implantation was evaluated.
Assessing the uptake and effectiveness of a quick reference guide to antibiotic prescribing in Australian general practice
Authors: Thompson Angus , O'Sullivan Patrick , Banham Elisabeth , Peterson Greg
Published: July 2016

Prescribing guidelines are an essential component of antimicrobial stewardship programs in Australian hospitals. Nonetheless, the majority of antibiotic prescribing occurs in the community and the effectiveness of guidelines developed specifically to meet the needs of Australian general practice is unknown. This study aims to assess the uptake and effectiveness of a quick reference guide to antibiotic prescribing among primary care prescribers. A quick reference guide to antibiotic prescribing was developed and prescribers in five Tasmanian practices were surveyed regarding use of this guide. Thirty-three surveys were returned and, of those answering specific sections, 75% were aware of the guide and 71% had used it within the last month. The guide affected the antibiotic prescribing practice of 74% of responding prescribers; most often on choice of antibiotic; but also on duration of treatment, dose and dosing frequency. A quick reference guide to antibiotic prescribing was well received by prescribers and may usefully support efforts to improve antimicrobial stewardship in the community.
Non-linear response of soil N2O emissions to nitrogen fertiliser in a cotton–fallow rotation in sub-tropical Australia
Authors: Scheer Clemens , Rowlings David W. , Grace Peter R.
Published: July 2016

Nitrogen (N) fertiliser is a major source of atmospheric nitrous oxide (N2O), and over recent years there has been growing evidence for a non-linear, exponential relationship between N fertiliser application rate and N2O emissions. However, there is still a high level of uncertainty around the relationship of N fertiliser rate and N2O emissions for many cropping systems. We conducted year-round measurements of N2O emission and lint yield in four N-rate treatments (0, 90, 180 and 270kgNha–1) in a cotton–fallow rotation on a black vertosol in Australia. We observed a non-linear exponential response of N2O emissions to increasing N fertiliser rates with cumulative annual N2O emissions of 0.55, 0.67, 1.07 and 1.89kgNha–1 for the four respective N fertiliser rates, but no N response to yield occurred above 180kgNha–1. The annual N2O emission factors induced by N fertiliser were 0.13, 0.29 and 0.50% for the 90, 180 and 270kgNha–1 treatments respectively, significantly lower than the IPCC Tier 1 default value of 1.0%. This nonlinear response suggests that an exponential N2O emissions model may be more appropriate for estimating emission of N2O from soils cultivated to cotton in Australia. It also demonstrates that improved agricultural N-management practices can be adopted in cotton to substantially reduce N2O emissions without affecting yield.
A power series formulation for two-dimensional wildfire shapes
Authors: Hilton J. E. , Miller C. , Sullivan A. L.
Published: July 2016

Computational simulations of wildfires require a model for the two-dimensional expansion of a fire perimeter. Although many expressions exist for the one-dimensional rate of spread of a fire front, there are currently no agreed mathematical expressions for the two-dimensional outward speed of a fire perimeter. Multiple two-dimensional shapes such as elliptical and oval-shaped perimeters have been observed and reported in the literature, and several studies have attempted to classify these shapes using geometric approximations. Here we show that a two-dimensional outward speed based on a power series results in a perimeter that can match many of these observed shapes. The power series is based on the dot product between the vector normal to the perimeter and a fixed wind vector. The formulation allows the evolution and shape of a fire perimeter to be expressed using a small set of scalar coefficients. The formulation is implemented using the level set method, and computed perimeters are shown to provide a good match to perimeters of small-scale experimental fires. The method could provide a framework for statistical matching of wildfire shapes or be used to improve current wildfire prediction systems.
Causal inference in economics and marketing
Authors: Varian Hal R.
Published: July 2016

This is an elementary introduction to causal inference in economics written for readers familiar with machine learning methods. The critical step in any causal analysis is estimating the counterfactual—a prediction of what would have happened in the absence of the treatment. The powerful techniques used in machine learning may be useful for developing better estimates of the counterfactual, potentially improving causal inference.
Recursive partitioning for heterogeneous causal effects
Authors: Athey Susan , Imbens Guido
Published: July 2016

In this paper we propose methods for estimating heterogeneity in causal effects in experimental and observational studies and for conducting hypothesis tests about the magnitude of differences in treatment effects across subsets of the population. We provide a data-driven approach to partition the data into subpopulations that differ in the magnitude of their treatment effects. The approach enables the construction of valid confidence intervals for treatment effects, even with many covariates relative to the sample size, and without “sparsity” assumptions. We propose an “honest” approach to estimation, whereby one sample is used to construct the partition and another to estimate treatment effects for each subpopulation. Our approach builds on regression tree methods, modified to optimize for goodness of fit in treatment effects and to account for honest estimation. Our model selection criterion anticipates that bias will be eliminated by honest estimation and also accounts for the effect of making additional splits on the variance of treatment effect estimates within each subpopulation. We address the challenge that the “ground truth” for a causal effect is not observed for any individual unit, so that standard approaches to cross-validation must be modified. Through a simulation study, we show that for our preferred method honest estimation results in nominal coverage for 90% confidence intervals, whereas coverage ranges between 74% and 84% for nonhonest approaches. Honest estimation requires estimating the model with a smaller sample size; the cost in terms of mean squared error of treatment effects for our preferred method ranges between 7–22%.
Quantity discounts on a virtual good: The results of a massive pricing experiment at King Digital Entertainment
Authors: Levitt Steven D. , List John A. , Neckermann Susanne , Nelson David
Published: July 2016

We report on a natural field experiment on quantity discounts involving more than 14 million consumers. Implementing price reductions ranging from 9–70% for large purchases, we found remarkably little impact on revenue, either positively or negatively. There was virtually no increase in the quantity of customers making a purchase; all the observed changes occurred for customers who already were buyers. We found evidence that infrequent purchasers are more responsive to discounts than frequent purchasers. There was some evidence of habit formation when prices returned to pre-experiment levels. There also was some evidence that consumers contemplating small purchases are discouraged by the presence of extreme quantity discounts for large purchases.
Lasso adjustments of treatment effect estimates in randomized experiments
Authors: Bloniarz Adam , Liu Hanzhong , Zhang Cun-Hui , Sekhon Jasjeet S. , Yu Bin
Published: July 2016

We provide a principled way for investigators to analyze randomized experiments when the number of covariates is large. Investigators often use linear multivariate regression to analyze randomized experiments instead of simply reporting the difference of means between treatment and control groups. Their aim is to reduce the variance of the estimated treatment effect by adjusting for covariates. If there are a large number of covariates relative to the number of observations, regression may perform poorly because of overfitting. In such cases, the least absolute shrinkage and selection operator (Lasso) may be helpful. We study the resulting Lasso-based treatment effect estimator under the Neyman–Rubin model of randomized experiments. We present theoretical conditions that guarantee that the estimator is more efficient than the simple difference-of-means estimator, and we provide a conservative estimator of the asymptotic variance, which can yield tighter confidence intervals than the difference-of-means estimator. Simulation and data examples show that Lasso-based adjustment can be advantageous even when the number of covariates is less than the number of observations. Specifically, a variant using Lasso for selection and ordinary least squares (OLS) for estimation performs particularly well, and it chooses a smoothing parameter based on combined performance of Lasso and OLS.
Estimating peer effects in networks with peer encouragement designs
Authors: Eckles Dean , Kizilcec René F. , Bakshy Eytan
Published: July 2016

Peer effects, in which the behavior of an individual is affected by the behavior of their peers, are central to social science. Because peer effects are often confounded with homophily and common external causes, recent work has used randomized experiments to estimate effects of specific peer behaviors. These experiments have often relied on the experimenter being able to randomly modulate mechanisms by which peer behavior is transmitted to a focal individual. We describe experimental designs that instead randomly assign individuals’ peers to encouragements to behaviors that directly affect those individuals. We illustrate this method with a large peer encouragement design on Facebook for estimating the effects of receiving feedback from peers on posts shared by focal individuals. We find evidence for substantial effects of receiving marginal feedback on multiple behaviors, including giving feedback to others and continued posting. These findings provide experimental evidence for the role of behaviors directed at specific individuals in the adoption and continued use of communication technologies. In comparison, observational estimates differ substantially, both underestimating and overestimating effects, suggesting that researchers and policy makers should be cautious in relying on them.
Damage control
Authors: Skelt Louise
Published: July 2016

When a problem of understanding arises for a hearing-impaired recipient in the course of a conversation, and is detected, repairing that problem is only one of several possible courses of action for participants. Another possibility is the collaborative closing of the part of the conversation which has proved problematic for understanding, to allow the initiation of a new, and potentially less problematic, topic. This paper examines one practice utilised by hearing-impaired interactants and their partners in achieving such closings. The action of withdrawal of engagement (via withdrawal of gaze at partner) by hearing impaired interactants, accompanied by their production of multi-unit turns at talk, brings about the closing of problematic sequences. It is proposed that these multi-unit turns address the interactional delicacy of recipients’ withdrawal of engagement at points where the speaker’s action is demonstrably incomplete. By initiating and cooperating with ‘strategic’ topic change in this way, participants act both to conceal the understanding problem and to avoid its potential consequences for the unfolding conversation. In doing so, they also act to keep issues of conversational competence, and the threats to face and identity which may arise from these issues, off the surface of the conversation.
Multilingualism in Australia
Authors: Rubino Antonia
Published: July 2016

This paper gives a critical overview of Australian research in the area of immigrant languages, arguing that this field of study is a significant component of the wider applied linguistics scene in Australia and has also contributed to enhancing the broad appreciation of the cultural and linguistic diversity of the country. It shows that research into immigrant languages has drawn upon a range of paradigms and evaluates those that have been most productively used. The paper argues that new research developments are needed to take into account the changing linguistic landscape of Australia and the increased fluidity and mobility of current migration.