bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rate dependencies and energy absorption characteristics of nanoreinforced, biofiber, and microcellular polymer composites
Authors: Argento Alan , Kim Wonsuk , Lee Ellen C. , Harris Angela M. , Mielewski Deborah F. 
Published: August 2011

AbstractThe effects of loading rate on bio‐, nano‐, and microcellular composite systems have been studied. Fiber–resin systems have been manufactured and dynamically tested at various speeds to assess their strain‐rate dependencies (rate hardening) and energy‐dissipation characteristics compared to conventional materials. The following composite systems have been fabricated and studied: polypropylene/sisal fiber biocomposite, hemp/vinyl ester biocomposite, thermoplastic olefin/nanoclay composite, microcellular polypropylene/sisal fiber biocomposite, and microcellular thermoplastic olefin/nanoclay composite. It has been determined that the biocomposite systems studied possess unique energy dissipation characteristics and muted rate dependence, while the nanocomposite system did not. In addition, microcellular foaming of these materials further enhanced the effects. Though the exact mechanisms at play are not fully understood at this point, it has been found that in addition to the microcellular voids, the anatomical vasculature of the natural fibers may play a role in energy dissipation processes in these hybrid materials. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Electron reflector to enhance photovoltaic efficiency: application to thin‐film CdTe solar cells
Authors: Hsiao Kuo‐Jui , Sites James R. 
Published: August 2011

ABSTRACTThe incorporation of an electron reflector is a proposed strategy to improve the open‐circuit voltage of CdTe solar cells. An electron reflector is a conduction‐band barrier that can effectively reduce electron recombination at the back surface. In this work, the electron‐reflector strategy is numerically applied to a thin‐film CdTe record‐cell baseline model (efficiency = 16.5%). Simulation shows that to have the optimal effect from an electron reflector, the CdTe thickness should be on the order of 1 µm, or slightly lower if the optical reflection at the back surface can be enhanced. Efficiency above 19% should be achievable with a 0.2‐eV electron reflector and currently achievable parameters (1014‐cm−3 hole density and 1‐ns lifetime). Moreover, efficiency above 20% should be possible at a 1‐µm absorber layer if large optical back reflection can also be achieved. Copyright © 2011 John Wiley & Sons, Ltd.
Care pathway clustering: issues for older adult mental health services
Authors: Whelan Paul , Zoha Mo , Ramcharitar Kristal , Andrews Tresa 
Published: August 2011

AbstractThe imminent payment‐by‐results system for mental health in England means that Trusts need to reorganise delivery of care taking into account the new care pathway clusters. In this article, Dr Whelan and colleagues discuss the potential dilemmas and problems faced by the introduction of this system based on their own experience, with a particular focus on old age services. Copyright © 2011 Wiley Interface Ltd
Synthesis of polymeric ionic liquid microsphere/Pt nanoparticle hybrids for electrocatalytic oxidation of methanol and catalytic oxidation of benzyl alcohol
Authors: Yang Jianhu , Qiu Lihua , Liu Baoqiang , Peng Yingjing , Yan Feng , Shang Songmin 
Published: August 2011

AbstractHerein, we present a facile approach for the synthesis of polymeric ionic liquids (PILs) microspheres for metal scavenging and catalysis. Crosslinked poly(1‐butyl‐3‐vinylimidazolium bromide) microspheres with the diameter of about 200 nm were synthesized via miniemulsion polymerization, in which 1,4‐di(vinylimidazolium) butane bisbromide was added as the crosslinker. Anion exchange of PIL microspheres with Pt precursor and followed by the reduction of Pt ions produced PIL microsphere supported Pt nanoparticle hybrids. The synthesized Pt nanoparticles with a diameter of about 2 nm are uniformly dispersed and strongly bound to the surface of PIL microspheres. The catalytic performances of PIL/Pt nanoparticle hybrids were evaluated for both the electrocatalytic oxidation of methanol and oxidation of benzyl alcohol. The PIL/Pt nanoparticle hybrids show better electrocatalytic activity towards the electrooxidation of methanol than pure Pt nanoparticles. Furthermore, they are effective and easily reusable catalysts for the selective oxidation of benzyl alcohol in aqueous reaction media, demonstrating that the synthesized PIL microspheres are suitable scaffolds for heterogeneous catalysts Pt. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Structure evolution of α′‐phase poly(lactic acid)
Authors: Chen Xiaolang , Kalish Jeffrey , Hsu Shaw Ling 
Published: August 2011

AbstractPoly(lactic acid) films consisting of α′‐forms were prepared and uniaxially drawn. The effects of the draw rate at temperatures above the glass transition temperature on chain conformation, degree of crystallinity, and crystalline phase transformation were investigated by a combination of vibrational spectroscopy (infrared and Raman), differential scanning calorimetry, and wide‐angle X‐ray diffraction (WAXD). It was established that the α′‐crystal's phase of poly(lactic acid) films does not transform into either an α or β crystals on uniaxial drawing at a fixed draw ratio of 4. However, the degree of crystallinity was significantly increased on deformation. The structural change as a function of deformation also promotes an increase in the strain‐induced enthalpic relaxation endothermic peak appearing near the glass transition region. While the overall changes in physical properties can be attributed to the changes in the degree of crystallinity as a function of strain rate, polarized Raman spectra, and WAXD clearly illustrated changes and the differences in the amorphous and crystalline orientation as a function of processing conditions. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1446–1454, 2011
Predicting the proton conductivity of perfluorosulfonic acid membrane via combining statistical thermodynamics and molecular dynamics simulation
Authors: Kim Young Gyun , Bae Young Chan 
Published: August 2011

AbstractThe electrochemical properties of a perfluorosulfonic acid (PFSA) membrane are estimated using a combination of molecular dynamics simulation and statistical thermodynamic model. We obtain all parameters in an ionic conductivity model from an atomistic simulation and remove all adjusted model parameters. From a microscopic point of view, the hydrated PFSA membrane shows micro‐phase segregation which separated into hydrophilic and hydrophobic phases. Our present work originates with this phenomenon and we treat this phase segregation as if it is a continuous phase for each of which the proton (H+) is transported inside the PFSA membrane/solvent (water and alcohols) mixture. The chemical potential for a given system is estimated using a molecular simulation technique to predict the van der Waals interaction energy between the polymer and solvent. In addition, the self diffusion coefficients are calculated from the molecular dynamics simulation. We study various polymer/solvent compositions to understand the concentration dependence of self diffusion coefficient. Our self diffusion coefficients and also the predicted final ionic conductivity agree well with previously reported experimental data. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1455–1463, 2011
High‐thermally stable and high‐bandwidth graded index plastic optical fiber for vehicle networks
Authors: Asai Makoto , Yamaki Yasushi , Takahashi Satoshi , Koike Yasuhiro 
Published: August 2011

AbstractRadial refractive index profiles within the graded index plastic optical fiber (GI‐POF) is formed by adding a dopant to a polymer. This addition of the dopant significantly decreased the Tg of the polymer due to the plasticization. This disadvantage made the installation of the GI‐POF difficult, especially in vehicle networks in which high thermal stability is required. We have suggested 9‐bromophenanthrene (BPT) as a novel dopant induced less plasticization for poly(methyl methacrylate) (PMMA) than the conventional dopants. However, although the fabricated GI‐POF using BPT had high enough thermal stability for vehicle networks, the attenuation was 800 dB/km and it could not be used. This high attenuation was caused by contaminant in the fabrication process of fibers. In this study, we succeeded to fabricate a GI‐POF with low‐attenuation and high‐thermal stability using highly pure BPT. Its attenuation was improved to 240 dB/km at 650 nm, which was enough transparency for vehicle networks. The Tg of the GIPOF was improved to 107 °C from 90 °C. The thermal stability of the GI‐POF below 85 °C/dry and 75 °C/85%RH was demonstrated to be as high as that of the commercially available step index POF. The bandwidth of the GI‐POF could be estimated over 4.0 GHz for the 50‐m fiber. These results demonstrated that our GI‐POF should qualify to be used in vehicle network. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1464–1469, 2011
Co‐existing paradoxical vocal cord motion and asthma in a young child
Authors: Saadoon Ammar A. , Ehlayel Mohammad 
Published: August 2011

AbstractWe are reporting a 7½‐year‐old child who had coexisting paradoxical vocal cord motion (PVCM) and asthma. There are only a few reported cases of PVCM in children younger than 10 years of age. Thus diagnosis mainly relies on high index of suspicion for these children. Missing PVCM diagnosis can lead to unnecessary diagnostic and therapeutic interventions to control asthma. We hope that this case report would increase the awareness of such coexistence in such a young age group. Pediatr Pulmonol. Pediatr Pulmonol. 2012; 47:96–98. © 2010 Wiley Periodicals, Inc.
Clinical investigation of respiratory system admittance in preschool children
Authors: Simpson Shannon J. , Straszek Sune P. , Sly Peter D. , Stick Stephen M. , Hall Graham L. 
Published: August 2011

AbstractIntroductionThe upper airway shunt attenuates measurements of respiratory system impedance (Zrs), with greater impact in young children. Changes in respiratory system admittance, Ars (or Zrs−1), are theoretically independent of the shunt. This study compared the ability of Ars, to standard oscillatory outcomes, to determine respiratory disease and differentiate responses to inhaled bronchial challenges in the clinical setting.MethodsThe forced oscillation technique (FOT) was used to establish reference equations for Ars in healthy preschool children, compare the change in Ars to standard oscillatory outcomes during bronchial challenge with inhaled adenosine‐5′‐monosphate (AMP) and to inhaled bronchodilator in healthy children and those with respiratory disease.ResultsChildren with respiratory disease had lower baseline Ars than healthy children (P < 0.05). However, there was no improved ability for Ars to differentiate between bronchodilator responses in healthy and disease populations. In contrast, the response to inhaled AMP occurred at a lower concentration, [25 (3.12–400) mg ml−1; median (10th–90th centile)], as measured by Ars when compared to respiratory system resistance [225 (6.25–400) mg ml−1; P = 0.016].ConclusionThis study supports the use of Ars during inhaled challenges, but not in response to bronchodilation. Pediatr Pulmonol. Pediatr Pulmonol. 2012; 47:53–58. © 2010 Wiley Periodicals, Inc.
Bronchoscopic techniques for removal of foreign bodies in children's airways
Authors: Rodrigues Ascedio Jose , Scussiatto Evandro Alencar , Jacomelli Márcia , Scordamaglio Paulo Rogério , Gregório Marcelo Gervilla , Palomino Addy Lidvina Mejía , Oliveira Eduardo Quintino , Figueiredo Viviane Rossi 
Published: August 2011

AbstractIntroductionThe management of airway foreign bodies (AFB) can be a dramatic situation in the emergency treatment of children and different techniques have been used to improve the therapeutic success and minimize risks.Objectiveto describe the bronchoscopic techniques used in the treatment of AFB in children referred to the Service of Respiratory Endoscopy of HC‐FMUSP.Patients and methodsRetrospective analysis of 78 children who underwent bronchoscopy for foreign body removal, at our Service from February 2003 to April 2008.Results78 patients with an AFB, aged 08 months to 14 years, with 39 being organic and 39 inorganic foreign bodies. Nine foreign bodies were located in the central airway (four in the larynx and five in the trachea), 34 in the right bronchial tree and 33 in the left bronchial tree. There was bilateral aspiration in two cases. All patients were initially submitted to diagnostic flexible bronchoscopy. A rigid bronchoscope was used in 39 cases; a flexible bronchoscope in 23 and an association of techniques in 15 cases (rigid bronchoscopy, flexible bronchoscopy, suspension laryngoscopy, and fluoroscopy).DiscussionAlthough the rigid bronchoscopy is considered the main tool for the removal of foreign bodies from airways, other useful techniques deserve attention as part of the medical training.ConclusionThe knowledge and association of different methods in pediatric bronchoscopy add the benefits of one method to another, minimizing the chances of therapeutic failure. Pediatr Pulmonol. 2012; 47:59–62. © 2010 Wiley Periodicals, Inc.
Comparison of pressure‐, flow‐, and NAVA‐Triggering in pediatric and neonatal ventilatory care
Authors: Ålander Merja , Peltoniemi Outi , Pokka Tytti , Kontiokari Tero 
Published: August 2011

AbstractObjectiveTo compare conventional trigger modes (pressure and flow trigger) to neurally adjusted ventilatory assist (NAVA), a novel sensing technique, and to observe the patient‐ventilator interactions during these modes.MethodsIn this prospective, crossover comparison study in tertiary care pediatric and neonatal intensive care unit, 18 patients (age from 30 weeks of postconceptional age to 16 years) needing mechanical ventilation were randomized. Three patients were excluded from the analysis because of problems in data collection. Patients were ventilated with three different trigger modes (pressure, flow, NAVA), for 10 min each. Patients were randomly allocated to six groups according to the order of trigger modes used.ResultsThe primary end point was the time in asynchrony between the patient and the ventilator. Secondary end points were peak and mean airway pressures (MAP), breathing frequency, tidal volume (TV), and vital parameters during each trigger mode. The proportion of time in asynchrony was significantly shorter in the NAVA group (8.8%) than in the pressure (33.4%) and flow (30.8%) groups (P < 0.001 for both). In the NAVA group, the peak inspiratory pressure was 2 to 1.9 cmH2O lower than in the pressure and flow groups, respectively (P < 0.05 for both) and the breathing frequency was 10 breaths/min higher than in the pressure group (P = 0.001). There was a tendency toward a lower MAP (P = 0.047) but the mean TV was about the same (6.4–6.8 ml/kg) in all three groups (P = 0.55). There were no differences in oxygen saturation or vital parameters between the groups.ConclusionNAVA offers a novel way of sensing patients' spontaneous breathing and significantly improves short‐term patient‐ventilator synchrony in a pediatric population. Pediatr Pulmonol. 2012; 47:76–83. © 2010 Wiley Periodicals, Inc.
Pre‐existing soft modes of motion uniquely defined by native contact topology facilitate ligand binding to proteins
Authors: Meireles Lidio , Gur Mert , Bakan Ahmet , Bahar Ivet 
Published: August 2011

AbstractModeling protein flexibility constitutes a major challenge in accurate prediction of protein–ligand and protein–protein interactions in docking simulations. The lack of a reliable method for predicting the conformational changes relevant to substrate binding prevents the productive application of computational docking to proteins that undergo large structural rearrangements. Here, we examine how coarse‐grained normal mode analysis has been advantageously applied to modeling protein flexibility associated with ligand binding. First, we highlight recent studies that have shown that there is a close agreement between the large‐scale collective motions of proteins predicted by elastic network models and the structural changes experimentally observed upon ligand binding. Then, we discuss studies that have exploited the predicted soft modes in docking simulations. Two general strategies are noted: pregeneration of conformational ensembles that are then utilized as input for standard fixed‐backbone docking and protein structure deformation along normal modes concurrent to docking. These studies show that the structural changes apparently “induced” upon ligand binding occur selectively along the soft modes accessible to the protein prior to ligand binding. They further suggest that proteins offer suitable means of accommodating/facilitating the recognition and binding of their ligand, presumably acquired by evolutionary selection of the suitable three‐dimensional structure.
Structural and binding properties of metal ion chelators relevant to Alzheimer's disease. A theoretical investigation
Authors: Marino Tiziana , Pavelka Matej , Toscano Marirosa , Russo Nino 
Published: August 2011

AbstractThe Copper (II) and Zinc (II) affinities for clioquinol and N,N'‐bis[(5β‐D‐glucopyranosyloxy‐2‐hydroxy)benzyl]‐N,N'‐dimethyl‐ethane‐1,2‐diamine ligands, recently proposed as good chelators in the therapy of Alzheimer's disease, have been studied theoretically by employing density functional theory. Results show that both ligands have a higher affinity for the copper dication and indicate that the copper complex assumes a near planar coordination geometry while the zinc prefers tetrahedral topologies. Furthermore, from the computed OH bond dissociation energies of the isolated ligands, it is clear that both ligands can act as good free radical scavengers being their bond dissociation energies and ionization potentials close to that of tocopherol, which is chosen as reference compound. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Optimal impedance control based on body inertia for a hydraulically driven hexapod robot walking on uneven and extremely soft terrain
Authors: Irawan Addie , Nonami Kenzo 
Published: August 2011

AbstractThis paper presents the implementation of impedance control for a hydraulically driven hexapod robot named COMET‐IV, which can walk on uneven and extremely soft terrain. To achieve the dynamic behavior of the hexapod robot, changes in center of mass and body attitude must be taken into consideration during the walking periods. Indirect force control via impedance control is used to address these issues. Two different impedance control schemes are developed and implemented: single‐leg impedance control and center of mass‐‐based impedance control. In the case of single‐leg impedance control, we derive the necessary impedance and adjust parameters (mass, damping, and stiffness) according to the robot legs' configuration. For center of mass–based impedance control, we use the sum of the forces of the support legs as a control input (represented by the body's current center of mass) for the derived impedance control and adjust parameters based on the robot body's configuration. The virtual forces from the robot body's moment of inertia are adapted to achieve optimal control via a linear quadratic regulator method for the proposed indirect attitude control. In addition, a compliant switching mechanism is designed to ensure that the implementation of the controller is applicable to the tripod sequences of force‐based walking modules. Evaluation and verification tests were conducted in the laboratory and the actual field with uneven terrain and extremely soft surfaces. © 2011 Wiley Periodicals, Inc.
Correlation‐based visual odometry for ground vehicles
Authors: Nourani‐Vatani Navid , Borges Paulo Vinicius Koerich 
Published: August 2011

AbstractReliable motion estimation is a key component for autonomous vehicles. We present a visual odometry method for ground vehicles using template matching. The method uses a downward‐facing camera perpendicular to the ground and estimates the motion of the vehicle by analyzing the image shift from frame to frame. Specifically, an image region (template) is selected, and using correlation we find the corresponding image region in the next frame. We introduce the use of multitemplate correlation matching and suggest template quality measures for estimating the suitability of a template for the purpose of correlation. Several aspects of the template choice are also presented. Through an extensive analysis, we derive the expected theoretical error rate of our system and show its dependence on the template window size and image noise. We also show how a linear forward prediction filter can be used to limit the search area to significantly increase the computation performance. Using a single camera and assuming an Ackerman‐steering model, the method has been implemented successfully on a large industrial forklift and a 4×4 vehicle. Over 6 km of field trials from our industrial test site, an off‐road area and an urban environment are presented illustrating the applicability of the method as an independent sensor for large vehicle motion estimation at practical velocities. © 2011 Wiley Periodicals, Inc.
Dual‐tracked mobile robot for motion in challenging terrains
Authors: Shoval Shraga , Shapiro Amir 
Published: August 2011

AbstractIn this paper we present a novel design for a dual‐tracked mobile robot. The robot is designed for safe, stable, and reliable motion in challenging terrains, tunnels, and confined spaces. It consists of two tracked platforms connected with a semipassive mechanism. Sensors attached to the connecting mechanism provide redundant localization data that improve the vehicle's autonomous dead reckoning. Each tracked platform mechanically backs up the other platform, resulting in a more robust and reliable operation. The load share between the platforms enables a high payload‐to‐weight ratio even on soft and slippery terrains. The robot's configurations make it suitable for motion in confined spaces such as underground tunnels, collapsed structures, pipes, and caves. The paper presents the mechanical design of the robot, its kinematic model, stability analysis, and a motion planner. Experimental results conducted on prototype models in various types of environments verify the robot capabilities to operate successfully on challenging terrains. The dual‐tracked robot is capable of climbing slopes 50% steeper than a single robot can. Moreover, the improved odometry system shows high accuracy with 2% error of the total travel distance. © 2011 Wiley Periodicals, Inc.