bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation of nanostructural parameters and macromechanical behaviour of hyperbranched‐modified polypropylene using time‐resolved small‐angle X‐ray scattering measurements
Authors: Sari Morteza Ganjaee , Stribeck Norbert , Moradian Siamak , Zeinolebadi Ahmad , Bastani Saeed , Botta Stephan 
Published: October 2012

AbstractPolypropylene (PP) is modified utilizing a poly(ester amide)‐based hyperbranched polymer (PS). A maleic‐modified PP is used to enhance the compatibility. Usual tensile experiments are carried out. The nanocrystalline structure is studied using small‐angle X‐ray scattering (SAXS) while a uniaxial mechanical load is simultaneously applied. SAXS patterns are analysed using procedures written in PV‐WAVE. The chord distribution function (CDF) is calculated and nanostructural parameters such as long period (lp) and nanodeformation (ϵNano) are extracted. The correlations between macromechanical parameters and nanostructures are studied. Mechanical results show that PS has a plasticizing effect. Reactively blended samples demonstrate enhanced mechanical properties. SAXS patterns reveal a well‐known structure of PP as a peculiar architecture of the nanostructure. Crystalline branching occurs in a geometry that is known as a mother–daughter crystal lamellar structure, also called a crosshatching structure. It is concluded that adding PS distorts the stacking of crystalline domains. The structural information from SAXS patterns in reciprocal space is visualized in real space in the calculated CDFs. The CDFs indicate that in simple blends, lp of the crystalline stacks increases compared to blank PP. Nevertheless, reactively blended samples show an increase of lp compared to blank PP; however, they possess smaller lp compared to simple blends. © 2012 Society of Chemical Industry
Molecular orientation and composition at the surface of spin‐coated polyfluorene:Fullerene blend films
Authors: Anselmo Ana Sofia , Dzwilewski Andrzej , Svensson Krister , Moons Ellen 
Published: October 2012

AbstractThe surface composition in spin‐coated films of polyfluorene:fullerene blends was determined quantitatively by near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy. By comparing partial and total electron yield spectra, we found vertical compositional differences in the surface region. Furthermore, the orientation of the polymer chains was investigated by variable‐angle NEXAFS. Blend films of poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐co‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole] with [6,6]‐phenyl‐C61‐butyric acid methyl ester in two different blend ratios were studied. Results showed polymer enrichment of the surfaces for films with a polymer:fullerene weight ratio of 20:80 and of 50:50, spin‐coated from both chlorobenzene and chloroform solutions. The angular dependence of the NEXAFS spectra of the pure polymer films showed a preferential plane‐on orientation, which was slightly stronger in the subsurface region than at the surface. In blend films, this orientational preference was less pronounced and the difference between surface and subsurface vanished. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Viscoelasticity of nanobubble‐inflated ultrathin polymer films: Justification by the coupling model
Authors: Ngai K. L. , Prevosto Daniele , Grassia Luigi 
Published: October 2012

AbstractThe nanobubble inflation method is the only experimental technique that can measure the viscoelastic creep compliance of unsupported ultrathin films of polymers over the glass–rubber transition zone as well as the dependence of the glass transition temperature (Tg) on film thickness. Sizeable reduction of Tg was observed in polystyrene (PS) and bisphenol A polycarbonate by the shift of the creep compliance to shorter times. The dependence of Tg on film thickness is consistent with the published data of free‐standing PS ultrathin films. However, accompanying the shift of the compliance to shorter times, a decrease in the rubbery plateau compliance is observed. The decrease becomes more dramatic in thinner films and at lower temperatures. This anomalous viscoelastic behavior was also observed in poly(vinyl acetate) and poly (n‐butyl methacrylate), but with large variation in the change of either the Tg or the plateau compliance. By now, well established in bulk polymers is the presence of three different viscoelastic mechanisms in the glass–rubber transition zone, namely, the Rouse modes, the sub‐Rouse modes, and the segmental α‐relaxation. Based on the thermorheological complexity of the three mechanisms, the viscoelastic anomaly observed in ultrathin polymer films and its dependence on chemical structure are explained in the framework of the Coupling Model. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Low Temperature Deposition of Antibacterially Active Silicon Oxide Layers Containing Silver Nanoparticles, Prepared by Atmospheric Pressure Plasma Chemical Vapor Deposition
Authors: Beier Oliver , Pfuch Andreas , Horn Kerstin , Weisser Jürgen , Schnabelrauch Matthias , Schimanski Arnd 
Published: October 2012

AbstractThis study presents investigations to create antibacterially active thin films by using the atmospheric pressure plasma chemical vapor deposition technique. Silver nitrate solutions are sprayed and converted within the plasma to create and implement formed silver nanoparticles into a growing SiOx‐matrix in situ during the deposition step. Investigation of the films on their bactericidal activity using an Escherichia coli (E. coli) strain shows a strong antibacterial effect of the coatings and additionally a good stability against abrasive wear. The films are characterized by X‐ray photoelectron spectroscopy, SEM, energy dispersive X‐ray spectroscopy, and IR spectroscopy. magnified image
Fast and efficient combustion synthesis route to produce novel nanocarbons
Authors: Dąbrowska Agnieszka , Huczko Andrzej , Dyjak Sławomir 
Published: October 2012

AbstractWe report the preliminary results on simple one‐step chemical synthesis of exfoliated graphite and other carbon‐related nanostructures via a novel combustion synthesis route. We found previously that different solid carbonates could be decomposed to elements upon reducing in solid phase by using a strong reducers and the produced carbon vapors instantly condense towards 1‐D nanocarbons. Here such combustion processing is extended towards the direct heterogeneous, efficient, and autothermic high‐pressure reduction of gaseous carbon oxides (CO2 and CO) to elements using the following reducers: Li, Mg, Ca, B, Ti, Zr, and Al. The solid products (layered graphite and nanocarbides) were chemically purified and characterized using XRD, SEM, and Raman spectroscopy. magnified image
Charge stabilization by reaction center protein immobilized to carbon nanotubes functionalized by amine groups and poly(3‐thiophene acetic acid) conducting polymer
Authors: Szabó T. , Magyar M. , Németh Z. , Hernádi K. , Endrődi B. , Bencsik G. , Visy Cs. , Horváth E. , Magrez A. , Forró L. , Nagy L. 
Published: October 2012

AbstractA large number of studies have indicated recently that photosynthetic reaction center proteins (RC) bind successfully to nanostructures and their functional activity is largely retained. The major goal of current research is to find the most efficient systems and conditions for the photoelectric energy conversion and for the stability of this bio‐nanocomposite. In our studies, we immobilized the RC protein on multiwalled carbon nanotubes (MWNT) through specific chemical binding to amine functional groups and through conducting polymer (poly(3‐thiophene acetic acid), PTAA). Both structural (TEM, AFM) and functional (absorption change and conductivity) measurements has shown that RCs could be bound effectively to functionalized CNTs. The kinetics of the light induced absorption change indicated that RCs were still active in the composite and there was an interaction between the protein cofactors and the CNTs. The light generated photocurrent was measured in an electrochemical cell with transparent CNT electrode designed specially for this experiment.
A coupled energy transport and hydrological model for urban canopies evaluated using a wireless sensor network
Authors: Wang Zhi‐Hua , Bou‐Zeid Elie , Smith James A. 
Published: October 2012

AbstractWe propose a new surface exchange scheme coupling the transport of energy and water in urban canopies. The new model resolves the subfacet heterogeneity of urban surfaces, which is particularly useful for capturing surface exchange processes from vegetated urban surfaces, such as lawns or green roofs. We develop detailed urban hydrological models for surfaces consisting of either natural (soil and vegetation) or engineered materials with water‐holding capacity. The coupling of energy and water transport enables us to parametrize surface evaporation from different urban facets including soils, vegetation and water‐holding engineered surfaces. The new coupled model is evaluated using field measurement data obtained through a wireless sensor network deployed over the Princeton University campus. Comparison of model prediction and measured results shows that the proposed surface exchange scheme is able to predict widely varying surface temperatures for each subfacet with good accuracy. Different weather conditions and seasonal variability are found to have insignificant effect on the model performance. The new model is also able to capture the subsurface hydrological processes with reasonable accuracy, particularly for urban lawns. The proposed model is then applied to assess different mitigation strategies of the urban heat island effect.
ECOSYSTEM ENGINEERS MODULATE EXOTIC INVASIONS IN RIPARIAN PLANT COMMUNITIES BY MODIFYING HYDROGEOMORPHIC CONNECTIVITY
Authors: Corenblit D. , Steiger J. , Tabacchi E. , González E. , Planty‐Tabacchi A‐M 
Published: October 2012

ABSTRACTPatterns of native and exotic plant species richness and cover were examined in relation with ecosystem engineer effects of pioneer vegetation within the Mediterranean gravel bed river Tech, South France. The floristic composition was characterized according to two distinct vegetation types corresponding to two habitats with contrasted conditions: (i) open and exposed alluvial bars dominated by herbaceous communities; and (ii) islands and river margins disconnected from annual hydrogeomorphic disturbances and covered by woody vegetation. A significant positive correlation between exotic and native plant species richness and cover was observed for both vegetation types. However, significant differences in native and exotic species richness and cover were found between these two vegetation types. Higher values of total species richness and Shannon diversity were attained within the herbaceous vegetation type than within the woody type. These differences are most likely related to changes in local exposure to hydrogeomorphic disturbances driven by woody engineer plant species and to vegetation succession. A lower exotic species cover within the woody vegetation type than within the herbaceous type suggested an increase of resistance to invasion by exotic species during the biogeomorphic succession. The engineer effects of woody vegetation through landform construction resulted in a decrease of alpha (α) diversity at the patch scale but, in parallel, caused an increase in gamma (γ) diversity at the scale of the studied river segment. Our study corroborates recent investigations that support the theory of biotic acceptance of exotic species by native species at the local scale (generally <10 m2) within heterogeneous and disturbed environments. Furthermore, we suggest that in riparian contexts such as the River Tech exotic species trapp sediment at the same time as native species and thus contribute to the increase in ecosystem resistance during the biogeomorphic succession. Copyright © 2012 John Wiley & Sons, Ltd.
In‐Vitro Permeability of Neutral Polystyrene Particles via Buccal Mucosa
Authors: Teubl Birgit Johanna , Meindl Claudia , Eitzlmayr Andreas , Zimmer Andreas , Fröhlich Eleonore , Roblegg Eva 
Published: October 2012

AbstractDrugs can be absorbed well in the oral cavity, which eliminates problems related to intestinal and hepatic first‐pass metabolism. Although it is well‐established that nanoparticles are small enough to penetrate/permeate epithelial barriers, there is no clear understanding of how they interact with the buccal mucosa. This work provides useful information regarding particle properties with regard to mucosal uptake and can be used for the rational design of nanocarriers. In the buccal mucosa, the uptake of neutral polystyrene nanoparticles (PP) is size‐dependent. Compared to 25 and 50 nm particles, 200 nm PP particles penetrate into deeper regions of the mucosa. This is attributed to the structure of the buccal mucosa, i.e., mucus layer and microplicae. The particles permeate the mucus layer and deposit in ridge‐like folds of superficial buccal cells. Thus, the effects of thermodynamic driving forces and/or interparticle electrostatic repulsion are enhanced and cellular uptake might be reduced for smaller particle sizes.
Formation of Reversed Austenite in High Temperature Tempering Process and its Effect on Mechanical Properties of Cr15 Super Martensitic Stainless Steel Alloyed with Copper
Authors: Ye Dong , Li Jun , Jiang Wen , Su Jie , Zhao Kunyu 
Published: October 2012

AbstractFormation mechanism of the reversed austenite of Cr15 super martensitic stainless steel (SMSS) alloyed with copper after high temperature tempering was investigated by means of thermo‐calc software, transmission electron microscope (TEM), and X‐ray diffraction (XRD). The mechanical properties of the SMSS were also tested. The experimental results show that the reversed austenite with low dislocation density is formed at high temperature tempering processing. The transformation of the martensite to reversed austenite is a diffused phase transformation, and the growth of the reversed austenite is closely related to the diffusion process of Ni. The bulk reversed austenite with large amount of stacking faults is formed with the increase of the tempering temperature. The volume fraction of reversed austenite increases at first and then decreases with increasing tempering temperature, and the maximum amount of the reversed austenite is obtained at 650°C. The reversed austenite is unstable at the tempering temperature above 650°C and the martensitic phase transformation will occur at the following cooling process. The mechanical properties of Cr15 super martensitic stainless steel are significantly influenced by the volume fraction of reversed austenite.
The Effort of Being in a Fictional World: Upkeyings and Laminated Frames in MMORPGs
Authors: Linderoth Jonas 
Published: October 2012

AbstractOn the basis of ten months of fieldwork studying a role‐playing guild in the game World of Warcraft, this article shows that contrary to the idea that virtual worlds are seductive illusions, technology does not necessarily support players' feelings of being immersed in fictional worlds. Applying Goffman's frame theory, the author explains how role‐players in the game actively upkey elements from primary frameworks in order to create and uphold the frame of being in a fictional world. This kind of narrative immersion is rather hindered than facilitated by technology.
Kerr-AdS and its near-horizon geometry: perturbations and the Kerr/CFT correspondence
Authors: Dias Óscar J. C. , Santos Jorge E. , Stein Maren 
Published: October 2012

AbstractWe investigate linear perturbations of spin-sfields in the Kerr-AdS black hole and in its near-horizon geometry (NHEK-AdS), using the Teukolsky master equation and the Hertz potential. In the NHEK-AdS geometry we solve the associated angular equation numerically and the radial equation exactly. Having these explicit solutions at hand, we search for linear mode instabilities. We do not find any (non-)axisymmetric instabilities with outgoing boundary conditions. This is in agreement with a recent conjecture relating the linearized stability properties of the full geometry with those of its near-horizon geometry. Moreover, we find that the asymptotic behaviour of the metric perturbations in NHEK-AdS violates the fall-off conditions imposed in the formulation of the Kerr/CFT correspondence (the only exception being the axisymmetric sector of perturbations).
Characterization of a new alginate lyase from newly isolated Flavobacterium sp. S20
Authors: Huang Lishuxin , Zhou Jungang , Li Xiao , Peng Qiang , Lu Hong , Du Yuguang 
Published: October 2012

Abstract
Alginate lyase is a promising biocatalyst because of its application in saccharification of alginate for the production of biochemicals and renewable biofuels. This study described the isolation of a new alginate metabolizing bacterium, Flavobacterium sp. S20, from sludge samples and the characterization of its alginate lyase Alg2A. The alginate lyase gene, alg2A, was obtained by constructing and screening the genomic library of the strain S20 and overexpressed in Escherichia coli. Substrate specificity assays indicated Alg2A preferred poly-α-l-guluronate as a substrate over poly-β-d-mannuronate. In the saccharification process of a high content (10 %, w/v) of sodium alginate, the recombinant alginate lyase Alg2A yielded 152 of mM the reducing sugars after 69 h of reaction, and the amounts of oligosaccharides with a different degree of polymerization (DP) generated by Alg2A gradually accumulated without significant variation in the distribution of oligosaccharide compositions. These results indicated that Alg2A possessed high enzymatic capability for saccharifying the alginate, which could be used in saccharifying the alginate biomass prior to the main fermentation process for biofuels. In addition, Alg2A had a different endolytic reaction mode from both the two commercial alginate lyases and other alginate lyases from polysaccharide lyase family 7 owing to high yields of penta-, hex-, and hepta-saccharides in the hydrolysis products of Alg2A. Thus, Alg2A could be a good tool for the large-scale preparation of alginate oligosaccharides with high DP.
Effects of elevated CO2 on the nutrient compositions and enzymes activities of Nilaparvata lugens nymphs fed on rice plants
Authors: Zeng YunYun , Huang WenKun , Su Li , Wu Gang , Zhuang Jing , Zhao WanYun , Hua HongXia , Li JunSheng , Xiao NengWen , Xiong YanFei 
Published: October 2012

Abstract
Elevated CO2 may reduce the tolerance of Nilaparvata lugen (N. lugens) to adverse environmental factors through the biological and physiological degeneration of N. lugens. In an artificial climate box, under 375 and 750 μL L−1 CO2 levels, the rice stems nutrient content, the nutrient content and enzyme activities of N. lugens nymph fed on rice seedlings exposed to ambient and elevated CO2 were studied. The results showed that rice stems had significantly higher protein and total amino acid levels under ambient than elevated CO2 levels. Nymphs had significantly higher protein levels in the ambient CO2 treatment, while their glucose levels were significantly lower under ambient CO2 conditions. Significantly higher trypsin activity was observed in nymphs grown in elevated CO2. Significantly lower activities of the protective enzymes total superoxide dismutase and catalase were observed in the nymphs under ambient CO2. Meanwhile, the activity of the detoxification enzyme glutathione S-transferase was significantly higher in the ambient CO2 treatment. Measuring how energy and resources were allocated to enzymes in N. lugens nymphs under elevated CO2 conditions can provide a more meaningful evaluation of their metabolic tolerances to adverse climatic conditions.
The role and clinical implications of microRNAs in hepatocellular carcinoma
Authors: Zhao Xue , Yang Zhen , Li GuangBing , Li DongKai , Zhao Yi , Wu Yan , Robson Simon C. , He Lian , Xu YiYao , Miao RuoYu , Zhao HaiTao 
Published: October 2012

Abstract
Hepatocellular carcinoma (HCC) is common and one of the most aggressive of all human cancers. Recent studies have indicated that miRNAs, a class of small noncoding RNAs that regulate gene expression post-transcriptionally, directly contribute to HCC by targeting many critical regulatory genes. Several miRNAs are involved in hepatitis B or hepatitis C virus replication and virus-induced changes, whereas others participate in multiple intracellular signaling pathways that modulate apoptosis, cell cycle checkpoints, and growth-factor-stimulated responses. When disturbed, these pathways appear to result in malignant transformation and ultimately HCC development. Recently, miRNAs circulating in the blood have acted as possible early diagnostic markers for HCC. These miRNA also could serve as indicators with respect to drug efficacy and be prognostic in HCC patients. Such biomarkers would assist stratification of HCC patients and help direct personalized therapy. Here, we summarize recent advances regarding the role of miRNAs in HCC development and progression. Our expectation is that these and ongoing studies will contribute to the understanding of the multiple roles of these small noncoding RNAs in liver tumorigenesis.
Feasible path planning for fixed-wing UAVs using seventh order Bézier curves
Authors: Neto Armando Alves , Macharet Douglas G. , Campos Mario F. M. 
Published: October 2012

Abstract
This study presents a novel methodology for generating smooth feasible paths for autonomous aerial vehicles in the three-dimensional space based on a variation of the Spatial Quintic Pythagorean Hodographs curves. Generated paths must satisfy three main constraints: (i) maximum curvature, (ii) maximum torsion and (iii) maximum climb (or dive) angle. A given path is considered to be feasible if the main kinematic constraints of the vehicle are not violated, which is accomplished in our approach by connecting different waypoints with seventh order Bézier curves. This also indirectly insures the smoothness of the vehicle’s acceleration profile between two consecutive points of the curve and of the entire path by controlling the curvature values at the extreme points of each composing Bézier curve segment. The computation of the Pythagorean Hodograph is cast as an optimization problem, for which we provide an algorithm with fast convergence to the final result. The proposed methodology is applicable to vehicles in three-dimensional environments, which can be modeled presuming the imposed constraints. Our methodology is validated in simulation with real parameters and simulated flight data of a small autonomous aerial vehicle.