bluuebunny/crossref_metadata_2025_split huggingface dataset:
The investigation of a new moderate water shutoff agent: Cationic polymer and anionic polymer
Authors: Dai Caili , Zhao Guang , You Qing , Zhao Mingwei 
Published: May 2013

ABSTRACTCationic polymers and anionic polymers were selected as a moderate water shutoff agent for water production control. Due to the adsorption of polymers on the sand surface, the adsorption capacity under static condition, in porous media, and adsorption morphology on mica were investigated through starch–cadmium iodide method, core flow test, and atomic force microscopy measurement. The adsorption quantity on the sand surface increased with the high polymer concentrations and long adsorption time. With the increase of temperature and shearing time, the adsorption capacity slightly decreased. In addition, the adsorption capacity under water wettability condition was significantly larger than that under oil wettability condition. Alternate injection of cationic polymer and anionic polymer caused larger adsorption capacity in the core test. An adsorption multilayer was formed through alternate adsorption of cationic polymer and anionic polymer confirmed by atomic force microscopy. The visual simulation experiment was also conducted to illustrate adsorption and enhanced oil recovery mechanism. The polymers preferentially entered the high permeability zone and adsorbed on the sand surface, thus enhanced oil recovery. Furthermore, alternate injection of cationic and anionic polymers as a moderate water shutoff agent was successfully applied for water production control in oilfield test. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39462.
Properties and nanoscale structure of polypropylene‐layered double hydroxide composites prepared by compatibilizer‐free way
Authors: Araújo Rafael S. , Grafova Iryna , Marques Maria de Fátima Vieira , Kemell Marianna , Leskelä Markku , Grafov Andriy 
Published: May 2013

ABSTRACTPolypropylene (PP) is the second most widespread commodity polyolefin. Even a small quantity of inorganic component is sufficient to achieve significant improvement of stiffness, strength, thermal stability, biodegradability, etc. The major drawback of inorgano‐organic composite materials is insufficient compatibility of the PP matrix with inorganic filler. A suitable choice of the layered double hydroxide‐modifying anion opens a possibility to obtain PP‐inorganic nanocomposites without a need to use compatibilizers like maleic anhydride grafted PP. The nanocomposites were prepared by melt blending in a twin‐screw mini‐extruder and characterized by dynamic mechanical thermal analysis, and electron microscopy. Nonpolar PP matrix mix uniformly with clay organophilized with functionalized surfactant acids, giving rise to composites with improved thermo‐mechanical properties. Influences of the anionic modifier and the filler content (2 or 5% w/w) on mechanical properties and nanoscale structure of the composites are discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2429–2438, 2013
Changes in a coral reef fishery along a gradient of fishing pressure in an Indonesian marine protected area
Authors: Campbell S. J. , Mukminin A. , Kartawijaya T. , Huchery C. , Cinner J. E. 
Published: May 2013

ABSTRACTHuman population growth, rising incomes, and increased commercialization of marine resources promote demand for reef fish, yet few studies in Indonesia have examined how artisanal fisheries are influenced by the socio‐cultural conditions that contribute to their exploitation. This study examined artisanal fisheries of Karimunjawa National Park, Java, to understand how the condition of an artisanal fishery was related to socio‐cultural factors, along a gradient in fishing pressure.A total of 8674 fishes landed in Karimunjawa by fishers using four artisanal fishing gears were examined to understand how the condition of the artisanal fishery (standard and infinite fish length, trophic level and weight) related to fishing gear use, village fishing grounds, management, human population size, human population density and estimated fishing pressure.Depletion in fish lengths and trophic structure were found at or above 46 fishing trips day‐1 km‐2, suggesting that fishing pressure is a key factor driving fishery catch structure. When catch characteristics were examined in relation to the fishing pressure estimates from each village, negative correlations were found between inshore fishing pressure (no. trips day‐1 km‐2) and all four fish catch characteristics, but owing to small sample sizes (n = 5), only the effects on trophic level were significant.Fishery closures had limited impact on fish characteristics, and lack of any effect of spatial controls on fishing also supports the notion that fishing pressure and the types of fishing gears used, most likely driven by human population densities, are the greatest drivers of reef fish catch characteristics in the Karimunjawa fishery.In the absence of support for fishery closures from local fishing communities or adequate enforcement of fishery closures, targeted gear or species management strategies that limit impacts on large‐bodied fish and aim to conserve key species may be more effective in improving the size and trophic structure of fish populations.Copyright © 2013 John Wiley & Sons, Ltd.
Donor–Acceptor Oligoimides for Application in High‐Performance Electrical Memory Devices
Authors: Lai Yi‐Cang , Kurosawa Tadanori , Higashihara Tomoya , Ueda Mitsuru , Chen Wen‐Chang 
Published: May 2013

AbstractTwo new oligoimides, OI(APAP-6FDA) and OI(APAN-6FDA), which consisted of electron‐donating N‐(4‐aminophenyl)‐N‐phenyl‐1‐aminopyrene (APAP) or N‐(4‐aminophenyl)‐N‐phenyl‐1‐aminonaphthalene (APAN) moieties and electron‐accepting 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) moieties, were designed and synthesized for application in electrical memory devices. Such devices, with the indium tin oxide (ITO)/oligoimide/Al configuration, showed memory characteristics, from high‐conductance Ohmic current flow to negative differential resistance (NDR), with corresponding film thicknesses of 38 and 48 nm, respectively. The 48 nm oligoimide film device exhibited NDR electrical behavior, which resulted from the diffusion of Al atoms into the oligoimide layer. On further increasing the film thickness to 85 nm, the OI(APAP-6FDA) film device showed a reproducible nonvolatile “write once read many” (WORM) property with a high ON/OFF current ratio (more than ×104). On the other hand, the device that was based on the 85 nm OI(APAN-6FDA) film exhibited a volatile static random access memory (SRAM) property. The longer conjugation length of the pyrene unit compared to that of a naphthalene unit was considered to be responsible for the different memory characteristics between these two oligoimides. These experimental results suggested that tunable switching behavior could be achieved through an appropriate design of the donor–acceptor oligoimide structure and controllable thickness of the active memory layer.
Cetylpyridinium Chloride Activated Trinitrotoluene Explosive Lights Up Robust and Ultrahigh Surface‐Enhanced Resonance Raman Scattering in a Silver Sol
Authors: Liu Honglin , Lin Dongyue , Sun Yudie , Yang Liangbao , Liu Jinhuai 
Published: May 2013

AbstractSurface‐enhanced resonance Raman scattering (SERRS) is not realized for most molecules of interest. Here, we developed a new SERRS platform for the fast and sensitive detection of 2,4,6‐trinitrotoluene (TNT), a molecule with low Raman cross section. A cationic surfactant, cetylpyridinium chloride (CPC) was modified on the surface of silver sols (CP‐capped Ag). CPC not only acts as the surface‐seeking species to trap sulfite‐sulfonated TNT, but also undergoes complexation with it, resulting in the presence of two charge‐transfer bands at 467 and 530 nm, respectively. This chromophore absorbs the visible light that matches with the incident laser and plasmon resonance of Ag sols by the use of a 532.06 nm laser, and offered large resonance Raman enhancement. This SERRS platform evidenced a fast and accurate detection of TNT with a detection limit of 5×10−11 M under a low laser power (200 μW) and a short integration time (3 s). The CP‐capped Ag also provides remarkable sensitivity and reliable repeatability. This study provides a facile and reliable method for TNT detection and a viable idea for the SERS detection of various non‐resonant molecules.
Identification of the Structural Determinants for Anticancer Activity of a Ruthenium Arene Peptide Conjugate
Authors: Meier Samuel M. , Novak Maria , Kandioller Wolfgang , Jakupec Michael A. , Arion Vladimir B. , Metzler‐Nolte Nils , Keppler Bernhard K. , Hartinger Christian G. 
Published: May 2013

AbstractOrganometallic Ru(arene)–peptide bioconjugates with potent in vitro anticancer activity are rare. We have prepared a conjugate of a Ru(arene) complex with the neuropeptide [Leu5]‐enkephalin. [Chlorido(η6‐p‐cymene)(5‐oxo‐κO‐2‐{(4‐[(N‐tyrosinyl‐glycinyl‐glycinyl‐phenylalanyl‐leucinyl‐NH2)propanamido]‐1H‐1,2,3‐triazol‐1‐yl)methyl}‐4H‐pyronato‐κO)ruthenium(II)] (8) shows antiproliferative activity in human ovarian carcinoma cells with an IC50 value as low as 13 μM, whereas the peptide or the Ru moiety alone are hardly cytotoxic. The conjugation strategy for linking the Ru(cym) (cym=η6‐p‐cymene) moiety to the peptide involved N‐terminal modification of an alkyne‐[Leu5]‐enkephalin with a 2‐(azidomethyl)‐5‐hydroxy‐4H‐pyran‐4‐one linker, using CuI‐catalyzed alkyne–azide cycloaddition (CuAAC), and subsequent metallation with the Ru(cym) moiety. The ruthenium‐bioconjugate was characterized by high resolution top‐down electrospray ionization mass spectrometry (ESI‐MS) with regard to peptide sequence, linker modification and metallation site. Notably, complete sequence coverage was obtained and the Ru(cym) moiety was confirmed to be coordinated to the pyronato linker. The ruthenium‐bioconjugate was analyzed with respect to cytotoxicity‐determining constituents, and through the bioconjugate models [{2‐(azidomethyl)‐5‐oxo‐κO‐4H‐pyronato‐κO}chloride (η6‐p‐cymene)ruthenium(II)] (5) and [chlorido(η6‐p‐cymene){5‐oxo‐κO‐2‐([(4‐(phenoxymethyl)‐1H‐1,2,3‐triazol‐1‐yl]methyl)‐4H‐pyronato‐κO}ruthenium(II)] (6) the Ru(cym) fragment with a triazole‐carrying pyronato ligand was identified as the minimal unit required to achieve in vitro anticancer activity.
Layer‐by‐Layer Assembly of Ferrocene‐Modified Linear Polyethylenimine Redox Polymer Films
Authors: DeLuca Jared L. , Hickey David P. , Bamper Daniel A. , Glatzhofer Daniel T. , Johnson Matthew B. , Schmidtke David W. 
Published: May 2013

AbstractHerein, both electrostatic and covalent layer‐by‐layer assembly were used for the construction of multicomposite thin films using a ferrocene‐modified linear poly(ethylenimine) redox polymer (Fc‐C6‐LPEI) as the cationic polyelectrolye, and poly(acrylic acid) (PAA), poly(glutamic acid) (PGA), or glucose oxidase (GOX) as the negative polyelectrolyte. The assembly of the multilayer films was characterized by cyclic voltammetry (CV), UV/Vis spectroscopy, and ellipsometry with the enzymatic response of the films containing GOX being characterized via constant potential amperometry. CV measurements suggested that the successful buildup of multilayer films was dependent upon the nature of the anionic polyelectrolyte used. Electrostatic assembly of films composed of Fc‐C6‐LPEI and either PAA or PGA produced large oxidation peak current densities of 630 and 670 μA cm−2, respectively, during cyclic voltammetry. Increased measured absorbance by UV/Vis spectroscopy and increased measured film thicknesses (400–600 nm) by ellipsometry provided additional evidence of successful film formation. In contrast, the films incorporating GOX that were electrostatically assembled surprisingly produced significantly lower electrochemical responses (12 μA cm−2), low absorbance values, and reduced film thicknesses (∼15 nm), and glucose electro‐oxidation current densities less than 1 μA cm−2, which all suggested unstable or minimal film formation. Subsequently, we developed a covalent layer‐by‐layer approach to fabricate films of Fc‐C6‐LPEI/GOX by covalently linking the amine groups of Fc‐C6‐LPEI to the aldehyde groups of periodate‐oxidized glucose oxidase. Covalent assembly of the Fc‐C6‐LPEI/GOX films produced oxidation peak current densities during cyclic voltammetry of 40 μA cm−2 and glucose electro‐oxidation current densities of 220 μA cm−2. These films also showed an increase in their thicknesses (∼140 nm) relative to the electrostatic GOX films. For the films containing either PAA or PGA, the pH of the polymer solutions used for construction was found to have a significant effect on the response of the multilayer films, and the electrochemical response of the Fc‐C6‐LPEI/PAA, Fc‐C6‐LPEI/PGA, or covalently assembled Fc‐C6‐LPEI/GOX films could be tuned by varying the number of bilayers (n=1–16) in the film. These results are important because this is the first report of the use of the novel Fc‐C6‐LPEI redox polymer in the successful development of multicomposite layer‐by‐layer films. The electrochemical response achieved with the covalently assembled Fc‐C6‐LPEI/GOX films demonstrates that this redox polymer and layer‐by‐layer assembly technique can be used for possible biosensor and biofuel applications, and the success of multiple anionic polyelectrolytes could lead to additional applications with other enzyme systems.
Dynamics of Monolayer–Island Transitions in 2,7‐Dioctyl‐benzothienobenzthiophene Thin Films
Authors: Dohr Michael , Werzer Oliver , Shen Quan , Salzmann Ingo , Teichert Christian , Ruzié Christian , Schweicher Guillaume , Geerts Yves Henri , Sferrazza Michele , Resel Roland 
Published: May 2013

AbstractThe order in molecular monolayers is a crucial aspect for their technological application. However, the preparation of defined monolayers by spin‐coating is a challenge, since the involved processes are far from thermodynamic equilibrium. In the work reported herein, the dynamic formation of dioctyl‐benzothienobenzothiophene monolayers is explored as a function of temperature by using X‐ray scattering techniques and atomic force microscopy. Starting with a disordered monolayer after the spin‐coating process, post‐deposition self‐reassembly at room temperature transforms the initially amorphous layer into a well‐ordered bilayer structure with a molecular herringbone packing, whereas at elevated temperature the formation of crystalline islands occurs. At the temperature of the liquid‐crystalline crystal–smectic transition, rewetting of the surface follows resulting in a complete homogeneous monolayer. By subsequent controlled cooling to room temperature, cooling‐rate‐dependent kinetics is observed; at rapid cooling, a stable monolayer is preserved at room temperature, whereas slow cooling causes bilayer structures. Increasing the understanding and control of monolayer formation is of high relevance for achieving ordered functional monolayers with defined two‐dimensional packing, for future applications in the field of organic electronics.
Physical and Mental Health, Anxiety and Depressive Symptoms in Caregivers of Patients in Vegetative State and Minimally Conscious State
Authors: Pagani M. , Giovannetti A. M. , Covelli V. , Sattin D. , Raggi A. , Leonardi M. 
Published: May 2013

Caregivers of patients in vegetative state and minimally conscious state play a crucial role in the process of taking care and, as previous studies reported, they can suffer of high burden and negative health outcomes. The aim of this national cross‐sectional study was to assess whether physical and mental health of caregivers, considering gender differences, is related to the presence of depressive symptoms, anxiety, age and patient's disease duration. Four‐hundred and eighteen caregivers, 294 women and 124 men, completed the State Trait Anxiety Inventory‐Y, Beck Depression Inventory, second version and Short Form‐12. Hierarchical multiple regression analyses were performed to evaluate to which extent depressive and anxiety symptoms predict physical and mental health. Men reported higher levels of mental health state, whereas physical health was not different across gender. High levels of anxiety symptoms were associated to negative mental health outcomes in both genders, whereas depressive symptoms were found to impact on female's mental and physical health only. A comprehensive and cost‐effective screening of anxiety and depressive symptoms may help to identify determinants of health worsening in order to plan, when necessary, caregivers' support. Copyright © 2013 John Wiley & Sons, Ltd.Key Practitioner MessagesFemale caregivers of patients in vegetative state and minimally conscious state have poorer levels of mental health, whereas physical health is similar to men's.Anxiety symptoms are related to negative mental health outcomes in both male and female caregivers, whereas depressive symptoms are found to impact on female mental and physical health only.It is essential to consider and assess depressive and anxiety symptoms as they may contribute to caregivers' health worsening. This knowledge can lead to plan more comprehensive and tailored caregivers' supports and a better care for patients.
Influence of cultivar and harvest year on triglyceride composition of olive oils produced in Calabria (Southern Italy)
Authors: Giuffrè Angelo Maria 
Published: May 2013

AbstractOlive oils extracted from Italian cultivars in South West Calabria, Southern Italy were analyzed for their triglyceride composition, for three successive harvest years 2005‐2006‐2007. Three autochthonous cultivars from Calabria (Cassanese, Ottobratica and Sinopolese) and seven allochtonous cultivars (Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino and Picholine) were considered. All cultivars showed a trilinolein content ≤ 0.10% of the total triglycerides, the equivalent carbon number42 (ECN42) content was always less than 0.75% of the total triglycerides. Triolein ranged from a minimum of 28.60% ± 2.12 in Nocellara Messinese to a maximum of 48.25% ± 2.67 found in Coratina. This work demonstrates the presence of significant differences (ANOVA) for the different triglyceride compounds present in these olive oils, taking into consideration the cultivar and the harvest year.Practical applications: Practical applications for the study entitled “Influence of cultivar and harvest year on triglyceride composition of olive oils produced in Calabria (Southern Italy)” regard the possibility of knowing the triglyceridic composition of olive oil produced in South West Calabria (Southern Italy) from ten cultivars, three autochtonous from Calabria: Cassanese, Ottobratica and Sinopolese and seven allochtonous cultivars: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino and Picholine. It is very important to understand if and how cultivar and harvest year influence the triglyceridic composition. In addition, the adaptability of the allochthonous cultivars in a different geographical context can be also evaluated by comparing olive oil triglyceride data between autochthonous and allochthonous cultivars.
Chemical composition of household malodours – an overview
Authors: Hammond Christopher J. 
Published: May 2013

ABSTRACTModern lifestyles create plentiful opportunities for malodour generation and proliferation. A domestic dwelling provides a number of micro‐environments in which a range of malodour‐producing activities such as laundry, food preparation and necessary bodily functions take place. With a significant proportion of time spent indoors, there is increasing exposure to these micro‐environments. Knowledge of the chemical composition and, in particular, the key malodour components present in these situations, is crucial to understand how to limit their impact. This is a multi‐disciplinary undertaking, encompassing analytical measurements, physical–organic chemistry, biology and sensory evaluation. As a consequence information can be dispersed over a number of sources in the literature and is not always readily recognizable as malodour related. The current review addresses this situation, examining the state of knowledge of household malodour composition, covering in detail areas such as food preparation and disposal, indoor air concentrations and building emissions, and body effluents. Examples to illustrate these areas are presented and discussed. Copyright © 2013 John Wiley & Sons, Ltd.
A mass‐fraction‐based interface‐capturing method for multi‐component flow
Authors: Wu Z. D. , Sun L. , Zong Z. 
Published: May 2013

SUMMARYAn interface‐capturing method based on mass fraction is developed to solve the Riemann problem in multi‐component compressible flow. Equations of mass fraction with modified form, which is derived from conservative equations of mass, are employed here to capture the interface. By introducing mass fraction into Euler equations system, as well as other conservative coefficients, a quasi‐conservative numerical model is created. Numerical examples show that the mass fraction model performs well not only in multi‐component fluids modeled by simple stiffened gas equation of state (EOS) but also in that modeled by complex Mie–Grüneisen EOS. Moreover, the mass fraction model is applied to Riemann problem with piecewise EOS; the expression of which depends on density. It is found that the mass fraction model can well adapt to the analytic change in piecewise EOS and produce accuracy solutions with fewer unknown quantities, and the model can be easily extended to m‐component fluid mixture by using only m + 4 equations with no additional conditions. Copyright © 2013 John Wiley & Sons, Ltd.
A design of residual error estimates for a high order BDF‐DGFE method applied to compressible flows
Authors: Dolejší V. 
Published: May 2013

SUMMARYWe deal with the numerical solution of the non‐stationary compressible Navier–Stokes equations with the aid of the backward difference formula – discontinuous Galerkin finite element method. This scheme is sufficiently stable, efficient and accurate with respect to the space as well as time coordinates. The nonlinear algebraic systems arising from the backward difference formula – discontinuous Galerkin finite element discretization are solved by an iterative Newton‐like method. The main benefit of this paper are residual error estimates that are able to identify the computational errors following from the space and time discretizations and from the inexact solution of the nonlinear algebraic systems. Thus, we propose an efficient algorithm where the algebraic, spatial and temporal errors are balanced. The computational performance of the proposed method is demonstrated by a list of numerical experiments. Copyright © 2013 John Wiley & Sons, Ltd.
The effect of Si and S on the stability of bcc iron with respect to tetragonal strain at the Earth's inner core conditions
Authors: Cui Hang , Zhang Zhigang , Zhang Yigang 
Published: May 2013

AbstractThe Earth's inner core is primarily composed of iron, but the stable crystalline structure of iron under core conditions still remains uncertain. The body‐centered cubic (bcc) phase has been suggested as a possible candidate to explain the observed seismic complexity, but its stability at core conditions is highly disputed. In this study, we utilized thermodynamic integration techniques based on extensive first‐principles molecular dynamics simulations to analyze the combining effects of high temperature and impurities on the stability of bcc structure with respect to tetragonal strain. According to our simulations, a small amount of Si/S permitted by seismological data at high temperature increases the stability of the bcc structure at high pressure, but not enough to achieve complete stability. This means the bcc‐structured iron is highly unlikely to present in the Earth's inner core.