bluuebunny/crossref_metadata_2025_split huggingface dataset:
Landscape reorganization under changing climatic forcing: Results from an experimental landscape
Authors: Singh Arvind , Reinhardt Liam , Foufoula‐Georgiou Efi 
Published: May 2015

AbstractUnderstanding how landscapes respond to climate dynamics in terms of macroscale (average topographic features) and microscale (landform reorganization) is of interest both for deciphering past climates from today's landscapes and for predicting future landscapes in view of recent climatic trends. Although several studies have addressed macro‐scale response, only a few have focused on quantifying smaller‐scale basin reorganization. To that goal, a series of controlled laboratory experiments were conducted where a self‐organized complete drainage network emerged under constant precipitation and uplift dynamics. Once steady state was achieved, the landscape was subjected to a fivefold increase in precipitation (transient state). Throughout the evolution, high‐resolution spatiotemporal topographic data in the form of digital elevation models were collected. The steady state landscape was shown to possess three distinct geomorphic regimes (unchannelized hillslopes, debris‐dominated channels, and fluvially dominated channels). During transient state, landscape reorganization was observed to be driven by hillslopes via accelerated erosion, ridge lowering, channel widening, and reduction of basin relief as opposed to channel base‐level reduction. Quantitative metrics on which these conclusions were based included slope‐area curve, correlation analysis of spatial and temporal elevation increments, and wavelet spectral analysis of the evolving landscapes. Our results highlight that landscape reorganization in response to increased precipitation seems to follow “an arrow of scale”: major elevation change initiates at the hillslope scale driving erosional regime change at intermediate scales and further cascading to geomorphic changes at the channel scale as time evolves.
Research on properties of rigid polyurethane foam with heteroaromatic and brominated benzyl polyols
Authors: Guo Hong , Gao Qun , Ouyang Chunfa , Zheng Kangsheng , Xu Wei 
Published: May 2015

ABSTRACTRigid polyurethane foams (RPUFs) were prepared with specific heteroaromatic and brominated benzyl polyols. The mechanical properties and thermal stability were studied using dynamic mechanical analysis (DMA) and thermogravimetric analysis (TG). The limiting oxygen index (LOI) was used to investigate the flame retardancy of the RPUFs. The results showed that the glass transition temperature (Tg) of the RPUF prepared by heteroaromatic polyol was 182°C, demonstrating an improved thermal stability for this specific heteroaromatic polyol. Brominated benzyl polyol exhibited less negative influence on mechanical properties of the RPUFs at the same time of improving the flame retardancy. The LOI values increased with an increase in the brominated polyol content to 27.5%, and the char‐forming ability of the RPUF improved; the char residue rate reached 12.6% at 700°C, but it was only 6.2% without the flame retardant. Scanning electron microscope (SEM) and energy‐dispersive spectrometry (EDS) verified that the mechanism of flame retardancy was due to a synergistic effect of the gas phase and the condensed phase. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42349.
Synthesis of seaweed polysaccharide‐based polyvinylpyrrolidone copolymer with adhesive properties
Authors: Chhatbar Mahesh U. , Siddhanta Arup K. 
Published: May 2015

ABSTRACTPolyvinylpyrrolidone (PVP) grafted sulfated polysaccharide of the seaweed Cystoseira indica (CIsps) (CIsps‐graft‐PVP) was synthesized in aqueous medium under microwave irradiation in the presence of potassium persulfate (KPS), as a free radical initiator. Varying the reaction parameters, e.g., concentration of PVP and KPS, reaction time and temperature, optimum grafting condition was identified as the one having the highest grafting ratio (Gr 2.30) and grafting efficiency (Ge 0.92). The grafted copolymer was characterized by FT‐IR, 13C‐NMR and thermo gravimetric analysis (TGA). The 5% (w/v) dispersion of the new material CIsps‐graft‐PVP in water exhibited comparable binding properties with papers, polyethylene sheets, and wood pieces as against that of a commercial adhesive. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42383.
An UV‐curable epoxy acrylate oligomer with high refractive index containing fluorene: Preparation, characterization, and application
Authors: Chen Jia , Zhou Yuming , Ding Qinghua , He Man 
Published: May 2015

ABSTRACTIn this article, a novel UV‐curable epoxy acrylate oligomer (BPEFPGMA) with high refractive index is successfully prepared through semi‐esterification reaction of 9,9‐bis[4‐(2‐hydroxyethoxy)phenyl]fluorene and phthalic anhydride, followed by end‐caping of glycidyl methacrylate. After 15 times’ repetitions, the process and properties of this oligomer are stable and reliable. The resulting BPEFPGMA exhibited low solvent content (≤1600 ppm), low viscosity (1900–2500 mPa s at 60°C), high refractive index (1.587 ± 0.003 at 20°C), and normal Mw (2550–3536 g/mol). The coating formulations of 1.57 UV‐curable glue are mixed with BPEFPGMA as reactive oligomer. Through the technology of UV‐curing forming, the corresponding brightness enhancement films are obtained. The resulting films exhibit normal structure, excellent adhesion (5B), good scratch resistance (50 g), and good abrasion resistance (50 g). They show excellent performance, and have reached the quality standard for use in liquid crystal display industry. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42386.
Polyvinylbutyral‐assisted synthesis and characterization of SnS mesoporous fibers via electrospinning process
Authors: Hsu Kuo‐Chin , Wu Dong‐Yang , Lin Pei‐Ying , Fu Yaw‐Shyan , Liao Jiuun‐Der 
Published: May 2015

ABSTRACTTin sulfide (SnS) has the potential to be used as a low‐cost absorber material for applications in thin film photovoltaic solar cells. In this study, polyvinylbutyral/SnS (PVB/SnS) composite fibers were synthesized through a relatively simple electrospinning process. SnS mesoporous fibers were obtained from PVB/SnS composite fibers after sintering treatment at 500°C for 1 h in N2 atmosphere. The SnS mesoporous fibers were then characterized using X‐ray powder diffraction, scanning electron microscopy, thermogravimetric analysis, and transmission electron microscopy. The optical properties of SnS mesoporous fibers were also recorded by UV–vis absorption spectroscopy. The results showed that the synthesized SnS mesoporous fibers exhibited a single phase, stoichiometric composition, with good crystallinity, a size ranging from 100 to 200 nm, and a band gap of 1.49 eV. The as‐prepared SnS mesoporous fibers are thus a suitable material to achieve visible light absorption in a thin film solar cell. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42388.
Preparation of zirconia loaded poly(acrylate) antistatic hard coatings on PMMA substrates
Authors: Chang Chao‐Ching , Hsieh Chin‐Yuan , Huang Feng‐Hsi , Cheng Liao‐Ping 
Published: May 2015

ABSTRACTZirconia (ZrO2) nanoparticles were synthesized by hydrolysis and condensation of zirconium‐n‐propoxide (ZNP) in 1‐propanol at the presence of methacrylic acid (MA), serving as a chelating agent for ZNP. The formed nanoparticles were chemically modified by the UV‐curable coupling agent, 3‐(trimethoxysilyl)propyl methacrylate (MSMA). The modified particles were then crosslinked with the hexa‐functional monomer, dipentaerythritol hexaacrylate (DPHA), to produce transparent antistatic hard coatings on poly(methyl methacrylate) (PMMA) substrates. Sizes of the modified particles, as determined by the dynamic light scattering technique, fell over a small range of 2–20 nm. Chemical analyses of the particles and the coatings were performed using FTIR and/or solid 29SiNMR spectroscopy. Surface resistivities of the coatings were measured, and the results indicated that with inclusion of 10 wt % modified zirconia, surface resistivity of ∼109 Ω/sq could be achieved, which amounted to ∼6 order magnitude lower than that of the particle‐free polymeric binder. Furthermore, this antistatic coating was very hard with pencil hardness of 8–9H, and attached perfectly to the PMMA substrate according to the peel test. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42411.
Advanced ultra‐high molecular weight polyethylene/antioxidant‐functionalized carbon nanotubes nanocomposites with improved thermo‐oxidative resistance
Authors: Dintcheva Nadka Tzankova , Arrigo Rossella , Gambarotti Cristian , Carroccio Sabrina , Coiai Serena , Filippone Giovanni 
Published: May 2015

ABSTRACTMultiwalled carbon nanotubes (CNTs) functionalized with hindered phenol moieties are dispersed in ultra‐high molecular weight polyethylene (UHMWPE), and the stabilizing action of the antioxidant (AO) functionalized CNTs (AO‐f‐CNTs) is studied through a combination of rheological and spectroscopic (FT‐IR) analyses. The effectiveness of two alternative compounding methods, namely hot compaction (HC) and melt mixing (MM), is compared. The combination of high temperature and mechanical stress experienced during MM brings about noticeable degradation phenomena of the matrix already in the course of the compounding step. Differently, the milder conditions of the HC process preserve the stability of the polymer, making this method preferable when dealing with highly viscous matrices. In addition, HC guarantees a better CNT dispersion, allowing for the maximization of the stabilizing action of the AO grafted on the nanotubes. As a result, the HC samples exhibit improved thermo‐oxidative resistance despite the very low amount of AO grafted onto the CNTs. Besides demonstrating the effectiveness of our AO‐f‐CNTs as stabilizers for polymer matrices, our results prove that CNTs can serve as a support on which grafting specific functional molecules to be dispersed in a host polymer matrix. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42420.
Poly(l‐lactide)/zno nanocomposites as efficient UV‐shielding coatings for packaging applications
Authors: Lizundia Erlantz , Ruiz‐Rubio Leire , Vilas José Luis , León Luis Manuel 
Published: May 2015

ABSTRACTPoly(l‐lactide) (PLLA)/ZnO nanocomposites have been developed as efficient UV‐shielding coatings for packaging applications. ZnO have been selected as the most suitable UV‐shielding material over 10 different metallic nanoparticles. Results reveal a nucleating effect of ZnO in which PLLA crystallization half time is reduced from 7.4 to 4.7 min with only 0.05 wt % ZnO. UV–vis spectroscopy confirms the UV‐shielding effect in PLLA/ZnO nanocomposites, where the ultraviolet spectrum is blocked by 61.2% for a concentration as low as 0.45 vol %, while the 95.9% of the visible radiation passes through the material. A schematic representation explaining obtained UV‐shielding effect is constructed based on the photon mean free path reduction as ZnO concentration increases. Water contact angle increased from 81° up to 91° for the 5 wt % nanocomposite, which would result beneficial in view to develop materials for packaging applications. Dynamic mechanical analysis exhibits a Tg increase with nanoparticle loading arising from the chain confinement caused by the presence of ZnO interacting surfaces. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42426.
Characterization of poly (N‐vinyl formamide) by size exclusion chromatography–multiangle light scattering and asymmetric‐flow field‐flow fractionation–multiangle light scattering
Authors: Zataray Julieta , Agirre Amaia , Carretero Paula , Meabe Leire , de la Cal José C. , Leiza Jose R. 
Published: May 2015

ABSTRACTThe molar mass and the radius of gyration of three poly N‐vinyl formamide (polyNVF) synthesized in aqueous solution polymerization were characterized using two different fractionation techniques: size exclusion chromatography (SEC) and asymmetric‐flow field‐flow fractionation (AF4) coupled with a multiangle light scattering (MALS) and a refractive index (RI) detector. For the sake of comparison, the polymers were also characterized by MALS using the Zimm plot approach (no fractionation). The dn dc−1 of the poly (N‐vinyl formamide) was measured (0.1564 mL g−1) and it was found to be insensitive to the molar mass (in the range 150–450 kDa) and also to the eluents used (DDI water or mixed eluent DDI water/acetonitrile (80 : 20) at pH = 5.5). Interestingly, the concentrations of the samples injected in the SEC and AF4 should be different because concentrations in the range of 20–40 mg mL−1 used for the AF4 caused overloading and anomalous elution in the SEC and hence misleading molar masses. At adequate concentrations in each fractionation equipment, the molar masses were in reasonable good agreement although AF4/MALS provided larger values than the other two techniques likely because samples were not filtered before injection. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42434.
Polypropylene reinforced with nanocrystalline cellulose: Coupling agent optimization
Authors: Hassanabadi Hojjat Mahi , Alemdar Ayse , Rodrigue Denis 
Published: May 2015

ABSTRACTFive different grades of maleic anhydride polypropylene (MAPP) having different molecular weight and acid value (AV) were used as coupler in PP‐nanocrystalline cellulose (NCC) composites. The main objective was to study the effect of MAPP structure (Mw, AV) and filler/coupler (F/C) ratio on mechanical properties in order to find optimum mechanical properties in tension, flexion, and impact. Results showed that both Mw and AV have direct effect on mechanical properties and a balance between both must be achieved to get the best performance. However, regardless of MAPP structure, optimum improvement was obtained for F/C = 7.5/1. Shear rheological data showed that at high MAPP content, MAPP acts as lubricant. DSC and AFM analysis showed small reduction in the size of PP crystals in the presence of NCC. Rheological data under large amplitude oscillatory shear showed that the nanocomposites used here are under percolation. Using these analyses, possible reinforcement mechanisms were investigated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42438.
Few‐layer‐graphene/polycarbonate nanocomposites as dielectric and conducting material
Authors: Sain P. K. , Goyal R. K. , Prasad Y. V. S. S. , Jyoti  , Sharma K. B. , Bhargava A. K. 
Published: May 2015

ABSTRACTAn attempt is taken to develop a flexible and light weight polycarbonate‐based nanocomposite system which could be successfully used as a dielectric material below percolation and as conducting material beyond percolation. The nanocomposite system has been prepared by solution mixing method in which few layer graphene was incorporated as conductive filler. X‐ray diffractometry, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy techniques were employed for characterization studies. The dielectric constant and conductivity were evaluated using precision impedance analyzer. Percolation threshold has been observed to occur at 3.5 wt % of few layer graphene. Dielectric constant of the nanocomposite system, in the smearing region, has been found to increase from ∼3.3 (without filler) to ∼70 (at 5 wt % FLG) with a dissipation factor of 0.07. The conductivity of the system was increased from 10−9 S/cm without FLG to 10−2 S/cm with 7 wt % of few layer graphene. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42443.
An investigation of sound absorption coefficient on sisal fiber poly lactic acid bio‐composites
Authors: Jayamani Elammaran , Hamdan Sinin , Rahman Md Rezaur , Bakri Muhammad Khusairy Bin , Kakar Akshay 
Published: May 2015

ABSTRACTIn this research, the mechanical, acoustical, thermal, morphological, and infrared spectral properties of untreated, heat and alkaline‐treated sisal fiber‐reinforced poly‐lactic‐acid bio‐composites were analyzed. The bio‐composite samples were fabricated using a hot press molding machine. The properties mentioned above were evaluated and compared with heat‐treated and alkaline‐treated sisal fibers. Composites with heat‐treated sisal fibers were found to exhibit the best mechanical properties. Thermo‐gravimetric analysis (TGA) was conducted to study the thermal degradation of the bio‐composite samples. It was discovered that the PLA‐sisal composites with optimal heat‐treated at 160°C and alkaline‐treated fibers possess good thermal stability as compared with untreated fiber. The results indicated that the composites prepared with 30wt % of sisal had the highest sound absorption as compared with other composites. Evidence of the successful reaction of sodium hydroxide and heat treatment of the sisal fibers was provided by the infrared spectrum and implied by decreased bands at certain wavenumbers. Observations based on scanning electron microscopy of the fracture surface of the composites showed the effect of alkaline and heat treatment on the fiber surface and improved fiber‐matrix adhesion. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42470.
A promising RVO4:Eu3+,Li+@SiO2 (R = Gd, Y and Gd/Y) red‐emitting phosphor with improved luminescence (cd/m2) and colour purity for optical display applications
Authors: Rambabu Urlagaddala , Munirathnam Nagegownivari Ramachandra , Reddy Busireddy Sudhakar , Chatterjee Sandip 
Published: May 2015

AbstractRed emission intensity was optimized in three stages, by investigating the effects of: (i) host composition (Gd, Y and Gd/Y), (ii) codoping Li+ as a sensitizer and, finally, (iii) with a SiO2 shell coating as a protecting layer. Lanthanide vanadate powder phosphors were synthesized using a modified colloidal precipitation technique. The effects of SiO2 coating on phosphor particles were characterized using scanning electron microscopy (SEM)‐EDAX, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and photoluminescence (PL) measurements. An improvement in the PL intensity on Li codoping was due to improved crystallinity, which led to higher oscillating strengths for the optical transitions, and also a lowering of the inversion symmetry of Eu3+ ions. Red emission intensity due to 5D0 → 5D2 transition of the phosphor Y0.94VO4:Eu3+0.05,Li+0.01 was enhanced by 22.28% compared with Y0.95VO4:Eu3+0.05, and was further improved by 58.73% with SiO2 coating. The luminescence intensity (I) and colour coordinates (x, y) of the optimized phosphor Y0.94VO4:Eu3+0.05,Li+0.01@SiO2, where I = 13.07 cd/m2 and (x = 0.6721, y = 0.3240), were compared with values for a commercial red phosphor (Y2O2S:Eu3+), where I = 27 cd/m2 and (x = 0.6522, y = 0.3437). The measured colour coordinates are superior to those of the commercial red phosphor, and moreover, match well with standard NTSC values (x = 0.67, y = 0.33). Copyright © 2015 John Wiley & Sons, Ltd.
Microfluidic wound model for studying the behaviors of Pseudomonas aeruginosa in polymicrobial biofilms
Authors: Wright Evan , Neethirajan Suresh , Weng Xuan 
Published: May 2015

ABSTRACTPseudomonas aeruginosa is a particularly problematic opportunistic pathogen due to its capacity to form recalcitrant biofilm structures, while cohabiting with other harmful/pathogenic species and harboring the capability to release toxins that cause tissue necrosis. Although it is now recognized that the majority of biofilm infections are polymicrobial, little is known about the complex interactions that occur within polymicrobial communities and few tools exist for studying these interactions. In this study, we have designed a microfluidic model that mimics the relevant physiological properties of wound microenvironment, while incorporating materials present in the human extracellular matrix/wound environment. Using microfluidics combined with imaging techniques, we have validated the robustness of our model comparing traditional GFP‐tagging to new fluorescent staining techniques to visualize/resolve individual species within a polymicrobial habitat. We have also demonstrated that chemotactic stimuli may be incorporated into our model through specialized ports in our chamber. Our system is specifically designed for use with high resolution imaging techniques, allowing for data collection throughout the life of the biofilm and in real‐time. Ultimately, this model can be used to investigate the spatio‐temporal mechanobiological structures of the wound environment, and the response of the bacteria to the drug transport which will significantly contribute to our understanding of the development and progression of polymicrobial biofilm infections. Biotechnol. Bioeng. 2015;112: 2351–2359. © 2015 Wiley Periodicals, Inc.
Hyperthermia approaches for enhanced delivery of nanomedicines to solid tumors
Authors: Frazier Nick , Ghandehari Hamidreza 
Published: May 2015

ABSTRACTDrug delivery to solid tumors has received much attention in order to reduce harmful side effects and improve the efficacy of treatment. Different strategies have been utilized with nanoparticle drug delivery systems, or nanomedicines, including passive and active targeting strategies, as well as the incorporation of stimuli sensitivity. Additionally, hyperthermia has been used in combination with such systems to further improve accumulation, localization, penetration, and subsequently efficacy. Localized hyperthermia within the solid tumor tissue can be applied through different mechanisms able to trigger vascular and cellular mechanisms for enhanced delivery of nanomedicines. This review covers the use of nanoparticles in drug delivery, the different methods for inducing localized hyperthermia, combination effects of hyperthermia, and successful strategies for improving the delivery of nanomedicines using hyperthermia. Biotechnol. Bioeng. 2015;112: 1967–1983. © 2015 Wiley Periodicals, Inc.