bluuebunny/crossref_metadata_2025 huggingface dataset:
Submicron nanoporous polyacrylamide beads with tunable size for verapamil imprinting
Authors: Nematollahzadeh Ali , Abdekhodaie Mohammad J. , Shojaei Akbar
Published: December 2011

Submicron sized polyacrylamide particles were prepared via modified precipitation polymerization method. Experimental design based on Taguchi approach was employed to study the influence of the polymerization composition including monomer (acrylamide), crosslinker (methylenebisacrylamide), initiator (azobisisobutyronitrile), and modifier (polyvinylpyrrolidone, K‐30), on the size and morphology of the particles. Varying the polymerization composition, submicron‐particles with sizes ranging between 100 and 600 nm were achieved. In all the cases, polydispersity index (PDI) of the particle size was found to be almost 1 indicating uniformity of the particle size. The concentration of crosslinker was found to be the most influential parameter on the particles size and the modifier concentration as an extra tunable parameter was believed to affect the nucleation mechanism and the viscosity of the medium to help controlling the particle size. To validate the optimization, particles with a preset diameter, i.e., 500 nm, were synthesized based on the composition predicted by the mathematical correlation. The polymer with the preset particle size was also imprinted with verapamil and characterized by FTIR, DSC, SEM, physisorption, elemental analysis, swelling, and batch rebinding experiments. The verapamil imprinted polymers bearing nano‐cavities exhibited high affinity with imprinting factor 2.17 towards the target molecule. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Linear and star branched perylene‐containing polyimides: Synthesis, characterization, and photovoltaic properties of novel donor–acceptor dyes used in solar cell
Authors: Niu Haijun , Luo Jun , Wu Wenjun , Mu Jingshan , Wang Cheng , Bai Xuduo , Wang Wen
Published: December 2011

A series of novel linear and star branched triphenylamine‐containing aromatic polyimides (AI, AII, AIII) were designed and synthesized by the condensation of 4‐aminotriphenylamine(I), 4,4′‐diamino triphenylamine(II), 4,4′,4″‐triamino triphenyl‐amine(III) with perylene‐3,4,9,10‐tetra‐carboxylic dianhydride to investigate the influence of topological structure on the energy levels and photophysical performance. The polyimides were characterized by elemental analysis, FTIR, and 1H‐NMR. The onset temperatures for 5% weight loss determined by thermoanalysis were between 415 and 428°C. The results of UV–vis spectra, quantum chemical calculation, and cyclic voltammetry revealed that introduction of triphenylamine group changed the energy levels of entire dye system. The aggregation way of polymers was also studied by the methods of UV–vis spectra, X‐ray diffraction (XRD), atom force microscopy, and the molecular simulation. The dye‐sensitized solar cells prepared by using the series of dyes showed big photoelectric response. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Morphology formation in polypropylene impact copolymers under static melt conditions: A simulation study
Authors: Remerie Klaas , Groenewold Jan
Published: December 2011

In this article, the equilibrium morphology of a typical polypropylene (PP) impact copolymer (ICP) system is investigated by numerical self‐consistent field simulations. The ICP was fractionated using temperature rising elution fractionation (TREF) to obtain the data necessary to define the simulation parameters. The results demonstrated the formation of a stratified droplet structure, in which ethylene content decreases from the center of the droplet toward the PP interface. This structure is shown to be in accordance with observations from transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. The components are confined to a narrow layer whose position is primarily determined by its ethylene content. Leakage into a neighboring layer occurs to a degree that is determined by the component molecular weight and the difference in ethylene content between the layers. Simulations for a range of droplet sizes enable calculation of the interfacial tension. A typical drawback of TREF involves the inability to fractionate the amorphous part, leading to a large difference in ethylene content between the matrix and its neighboring layers. Although this effect is shown not to have a significant influence on the stratified structure, it is shown to have a significant influence on the derived interfacial tension. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Oxygen barrier and mechanical properties of masterbatch‐based PA6/nanoclay composite films
Authors: Fasihi Mohammad , Abolghasemi Mohammad Reza
Published: December 2011

This study focuses on the possibility of improving performance properties of polyamide‐6 (PA6) nanocomposite films for packaging application using nanoclay masterbatch. Different concentrations of nanoclay in PA6 were prepared through melt‐mixing of particulate nanoclay and nanoclay masterbatches in a twin screw compounder, then film samples were molded using a hot press. Oxygen barrier properties were then measured and interpreted on the basis of different theoretical approaches. Also, a correlation between morphology and properties of the studied nanocomposites was observed, and all prepared nanocomposites exhibited performance improvement with increasing the nanoclay content. The masterbatch‐based nanocomposite films showed more exfoliated regions that leading to the enhancement of the mechanical properties. Gas permeability through nanocomposite films decreased significantly just by loading a small amount of nanoclay. However, surprising behavior in oxygen permeability observed at higher levels of nanoclay in masterbatch‐based nanocomposite was attributed to the decreased crystallinity of PA6 matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effectiveness of silane monomer on chitosan films and PCL‐based tri‐layer films
Authors: Sharmin Nusrat , Khan Ruhul A. , Salmieri Stéphane , Dussault Dominic , Lacroix Monique
Published: December 2011

Chitosan films were prepared by casting from its 1% (w/w) solution. Tensile strength (TS), tensile modulus (TM), and elongation at break (Eb%) of chitosan films were found to be 30 MPa, 450 MPa, and 8%, respectively. Silane monomer (3‐aminopropyl tri‐methoxy silane) (1–7%, w/w) was added into the chitosan solution (1%, w/w), and films were casted. The highest TS (38 MPa) and TM (620 MPa) values were found at 5% (w/w) silane content films. Polycaprolactone (PCL) films were prepared by compression molding; the values of TS, TM, and Eb of PCL films were found to be 12 MPa, 226 MPa, and 70%, respectively. Using chitosan and silane containing chitosan films, PCL‐based tri‐layer films were prepared by compression molding. Chitosan (also silane‐incorporated chitosan) content in the tri‐layer films varied from 10 to 50% by weight. The values of TS and TM of the silane containing composites were found to be 21 and 410 MPa, respectively, which is significantly higher (40% TS and 34% TM) than control composites. Molecular interactions due to silane addition were supported by FT‐IR analysis. The surface of the films and the interface of the tri‐layer films were investigated by scanning electron microscope (SEM). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Substrate effect on the crystallization of isotactic polypropylene
Authors: Lin Yuan , Fan Yurun
Published: December 2011

The evolution of storage modulus measured by a rotational rheometer shows that the isothermal crystallization of isotactic polypropylene (iPP) melts in contact with aluminum plates (PP‐Al) are considerably faster than that with stainless‐steel plates (PP‐SS). The difference is bigger at higher temperatures, and this behavior is opposite to that expected by our numerical simulation considering uniform bulk phase transition and substrate's ability to remove the latent heat. Polarized optical observations and surface energy evaluations via contact angle measurement indicate that surface energy of the substrates, including the effects of submicrometer morphology and roughness, should be the key factor to affect the crystallization of iPP. Transcrystallization zones, in which the nucleation density is controlled by the surface energy of substrates, were observed to grow toward the bulk with the thickness of about 0.2 mm for iPP to affect the global crystallization behavior. The critical value of surface energy of substrate to promote the interfacial crystallization of a polymer melt is derived, in terms of which the aluminum and stainless steel as well as optical glass, promote the surface nucleation with respect to the bulk nucleation of iPP. As a consequence, the conventional differential scanning calorimetry measurement mainly gives the heat fluxes of interfacial crystallization rather than the bulk crystallization due to the large surface‐to‐volume ratio of the specimen and the aluminum pan used which is a high surface energy substrate. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Adsorption behavior of As(III) onto chitosan resin with As(III) as template ions
Authors: Liu Bingjie , Lv Xin , Wang Dongfeng , Xu Ying , Zhang Li , Li Yujin
Published: December 2011

A novel, biobased chitosan resin was successfully synthesized, characterized, and applied for the selective removal of As(III) from aqueous solutions. Batch adsorption experiments were performed to evaluate its adsorption conditions, selectivity, and reusability. The results showed that the maximum adsorption capacity was 2.16 mg/g, observed at pH 6 and 40°C. Equilibrium adsorption was achieved within 8 h. The kinetic data, obtained at optimal pH 6, could be fitted with a pseudosecond order equation. Adsorption process could be well described by Langmuir adsorption isotherm model and the maximum adsorption capacity calculated from Langmuir equation was 4.45 mg/g. The selectivity coefficient of As(III) ions and other metal cation onto As‐ICR indicated an overall preference for As(III) ions, which was much higher than nonimprinted chitosan resins. Finally, the adsorption mechanisms were studied by Fourier transform infrared spectra, X‐ray diffraction, and differential scanning calorimetry analysis. The result reveals that the adsorption of As‐ICR for As(III) is a chelation process. These results earlier confirmed that As‐ICR is a very promising sorbent for selective adsorption of As(III) ions from aqueous solutions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Ion imprinted beads embedded cryogels for in vitro removal of iron from β‐thalassemic human plasma
Authors: Ergün Bahar , Baydemir Gözde , Andaç Müge , Yavuz Handan , Denizli Adil
Published: December 2011

Molecular recognition based Fe3+ imprinted poly(GMA‐MAC) (MIP) beads embedded PHEMA composite cryogel was prepared for selective removal of Fe3+ ions from β‐thalassemia patient plasma. The precomplexation was achieved by the coordination of Fe3+ ions with N‐methacryloyl‐(L)‐cysteine methyl ester (MAC‐Fe3+). MIP beads were prepared by dispersion polymerization in the presence of MAC‐Fe3+ complex and glycidyl methacrylate (GMA) monomer. Then the MIP beads were embedded into poly(hydroxyethyl methacrylate) (PHEMA) cryogel. The specific surface area and the swelling degree of the PHEMA‐MIP composite cryogel were found to be 76.8 m2/g and 7.7 g H2O/g cryogel, respectively. The maximum adsorption amount of Fe3+ ions was 2.23 mg/g. The relative selectivity of PHEMA‐MIP composite cryogel towards the Fe3+ ions was 135.0, 61.4, and 57.0 times greater than that of the PHEMA‐NIP cryogel as compared with the Ni2+, Zn2+, and Fe2+ ions, respectively. PHEMA‐MIP composite cryogel was recovered and reused many times without any significant decrease in its adsorption capacity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Mild synthesis of benzylated bamboo in LiCl/DMSO solution
Authors: Li Ming‐Fei , Sun Shao‐Ni , Xu Feng , Sun Run‐Cang
Published: December 2011

Benzylated bamboo was mildly synthesized in nonaqueous medium without mercerization pretreatment. The ball‐milled bamboo was firstly preswelled in lithium chloride/dimethyl sulfoxide (LiCl/DMSO) solution and then reacted with benzyl chloride in the presence of solid NaOH with varying molar ratios of benzyl chloride to OH groups of bamboo (1–4), reaction times (1–8 h), and temperatures (60–90°C). Benzylated bamboo products with yields from 51.1 to 106.9% and with degrees of substitution [DS, apparent value evaluated by Fourier transform infrared (FTIR) spectra] between 0.2 and 1.2 were synthesized. FTIR and 13C cross polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR) spectroscopy confirmed the incorporation of benzyl groups into bamboo; SEM observations of the highly benzylated bamboo showed porous surface with small irregular slices ascribed to the disruption of intermolecular and intramolecular hydrogen bonds between cellulose. Because of the degradation of amorphous components, the crystallinity decreased negligibly after modification and the thermal stability increased slightly but was lower than that of cellulose. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and characterization of new soluble multisite phase transfer catalysts and their catalysis in free radical polymerization of methyl methacrylate aided by ultrasound—A kinetic study
Authors: Murugan Eagambaram , Tamizharasu Gurusamy
Published: December 2011

Four different soluble phase transfer catalysts (PTCs) containing single, di, tri, and tetra active sites have been prepared and proved by FT‐IR, 1H NMR, 13C NMR, mass, elemental analysis, and conductivity measurement. The presence of the number of active sites in each catalyst was also been confirmed by determining their rate of polymerization of methyl methacrylate (MMA) using potassium peroxydisulfate (PDS) as a water soluble initiator in biphase medium. The comparative study reveals that the Rp of MMA determined in the presence of PTC combined with ultrasound has shown twofold enhancement in the activity than PTC alone. The observed order of activity was found to be of single‐site < di‐site < tri‐site < tetra‐site. Further, the thorough kinetic study of free radical polymerization of MMA has been investigated using superior tetra site viz., HBTAMPDTC and by varying the experimental parameters such as [MMA], [K2S2O8], [MPTC], and the temperature. Based on the observed kinetic results and activation parameters, a suitable mechanism was proposed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Surface modification of silica–PAN composite nanofibers induced by CO2‐pulsed laser
Authors: Salehi Esfandarani M. , Johari M. , Amrollahi R. , Karimi M.
Published: December 2011

In this study, the modification induced by CO2‐pulsed laser on the surface morphology of silica–polyacrylonitrile composite nanofibers has been investigated. Applied surface modification method is based on different infrared adsorption of materials. Two types of composite nanofibers containing silica nanoparticles with various diameters are irradiated with CO2‐pulsed laser of 1084 wavenumber (cm−1). Surface morphology of irradiated composite nanofibers was analyzed using field emission scanning electron microscope (FE‐SEM). FE‐SEM scans show characteristic modification on the surface of nanofibers with controlled distribution and dimension. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Formation mechanism of microvoids and microcracks of poly(vinyl chloride) under an artificial aging environment
Authors: Xiang Jun , Wang Jiliang , Chen Xiaofeng , Lei Jingxin
Published: December 2011

Degradation behaviors of both the unplasticized and plasticized poly(vinyl chloride) (UPVC and PPVC) under an artificial accelerating aging condition were extensively studied. The dependence of mechanical properties, average molecular weight (MW), and surface morphology of the earlier PVC on aging time was investigated by tensile tests, gel penetrate chromatogram (GPC), and scanning electron microscope (SEM), respectively. Fourier transform infrared and ultraviolet (UV)–visible spectroscopy were used to evaluate the probable formation of both the oxygen‐containing groups and the conjugated sequences during aging. The results reveal that UPVC is much easier to be degraded than PPVC under the same testing conditions. The irradiated surface is detected to change from an even topology into a rough topology initially, and then follows the appearance of many voids even cracks in the SEM morphology. During the aging process, oxygen‐containing groups and conjugation of PVC molecular chains around the cracks are observed, and noticeably increase with aging time. However, visible difference of the corresponding MWs of PVC before and after aging is not detected. Moreover, a novel degradation mechanism nearly related to the formation of microvoids and microcracks based on the cohesion energy of groups along PVC molecular chains is developed and semiquantitatively discussed. It is detected that the formation of microvoids and microcracks is attributed to both the thermodynamic changes of PVC backbone during the aging and the aggregation of oxygen‐containing groups with relatively large volumes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and properties of an amphoteric polycarboxylic acid‐based superplasticizer used in sulfoaluminate cement
Authors: Guo Wenjuan , Sun Na , Qin Jianjian , Zhang Jin , Pei Meishan , Wang Yingfei , Wang Shengnian
Published: December 2011

A novel amphoteric polycarboxylic (APC) acid‐based superplasticizer was prepared by solution copolymerization from maleic anhydride, allyl polyethylene glycol, and methacryloxyethyltrimethyl ammonium chloride (DMC). The cationic monomer DMC was introduced for improving the performances of sulfoaluminate cement (SAC) with APC. The condition on preparation of APC was determined by the orthogonal experiment, and the performances of fresh and hardened superplasticized mortars were assessed. APC was characterized by FTIR spectra. Adsorption amount and dispersing effectiveness of APC were also investigated. Results indicated that APC could improve the fluidity and enhance the mechanical performances of SAC mortars. Adsorption amount of APC in SAC is large. Compared with an anionic PC superplasticizer and a commercial superplasticizer Visco Crete 3390, APC has the better performance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Mechanical properties and fire retardant behavior of polyurethane foam reinforced with oil palm empty fruit bunch
Authors: Tay G. S. , Ong L. N. , Rozman H. D.
Published: December 2011

The objective of this study was to investigate the effects of isocyanate/hydroxyl ratio and ammonium polyphosphate (APP) content on the properties of polyurethane foam. Polyurethane (PU) foam was prepared from polymeric diphenylmethane diisocyanate and polyethylene glycol with molecular weight of 200, reinforced with oil palm empty fruit bunch (EFB) using one shot process. The effect of EFB content on the properties of PU foam was also studied. It was noticed that EFB enhanced the properties of the PU foam. This was due to EFB acting as hard segment in PU foam system. The NCO/OH ratio played an important role in determining the properties of the PU foam produced. However, since EFB is a highly flammable material, APP was introduced to the PU foam system. From the results, APP improved the fire retardant behavior of the PU foam. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Investigation of the surface area and polarity of porous copolymers of maleic anhydride and divinylbezene
Authors: Maciejewska M. , Szajnecki Ł. , Gawdzik B.
Published: December 2011

Porous copolymers of maleic anhydride (MA) and divinylbezene (DVB) in the form of regular microspheres were prepared by suspension polymerization. During copolymerization the mixture of 1,4‐dioxane and n‐dodecane as a pore‐forming diluent was used. It was found that specific surface area of the obtained beads is strongly dependent on the diluent system and polymerization medium and achieves a value from 4 to 535 m2/g. To determine the influence of polymerization medium on the selectivity and polarity of the copolymers, inverse gas chromatography (IGC) was applied. To determine these parameters, three procedures were applied: overall polarity, the selectivity triangle, and the ΔC method. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Graphite functionalization for dispersion in a two‐phase lubricant oligomer mixture
Authors: Kanniah Vinod , Wang Binghui , Yang Ying , Grulke Eric A.
Published: December 2011

Fluids with thermally conductive nanoparticles can provide improved heat transfer. Practical nanofluids will be likely based on lubricating oils for the continuous phase and systems that have extended service temperature ranges. A model system based on poly(α‐olefin) synthetic base oil modified with poly(dimethylsiloxane) to lower the mixture's pour point with graphite as a conductive additive was studied. Phase separation of the oligomer mixture occurred at temperatures less than ‐15°C. Graphite particles were etched using citric acid pretreatment to create hydroxyl and carboxyl groups on their surfaces. A coupling reaction between the hydroxyl groups on graphite and chloro groups on silanes gave rise to poly(α‐olefin)‐philic graphite particles. Similarly, a coupling reaction between the carboxyl groups on graphite surface and amine groups on silanes gave rise to poly(dimethylsiloxane)‐philic graphite particles. SEM, FT‐IR, and TG‐MS measurements were used to verify the presence of coupling agents on the surface and to estimate the thickness of the coatings. Upon separation of the mixture, each functionalized graphite type migrated exclusively to its preferred phase. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Biodegradable nanocomposites of cellulose acetate phthalate and chitosan reinforced with functionalized nanoclay: Mechanical, thermal, and biodegradability studies
Authors: Gaurav Aashish , Ashamol A. , Deepthi M. V. , Sailaja R. R. N.
Published: December 2011

Biodegradable nanocomposites of cellulose acetate phthalate and chitosan reinforced with functionalized nanoclay (NC) were prepared. The NC loading was varied from 0 to 10%. The mechanical and thermal properties have been investigated for these composites. The nanocomposites exhibited enhanced mechanical properties due to the addition of NC. The scanning electron micrographs of the blend specimens also support the above observations. Thermogravimetric analyses were carried out to assess the degradation stability of the blends. The blend shows an increase in the rate of biodegradation and water uptake with higher loading of NC. The exfoliation of NC was analyzed by X‐ray diffraction studies. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Mechanical, thermal, and biodegradation studies of polystyrene–phthalated starch blends using epoxy functionalized compatibilizer
Authors: Ashamol A. , Sailaja R. R. N.
Published: December 2011

Blends of polystyrene (PS) and esterified starch has been prepared using an epoxy functionalized PS as compatibilizer along with zinc stearate as prooxidant. The starch phthalate (Stph) loading was varied from 20 to 60%. The mechanical, thermal, and biodegradability studies of the blends were carried out as per the ASTM standards and the results were compared with that of neat PS. The blends exhibited enhanced mechanical properties with the addition of compatibilizer although the biodegradation rate slows down. The blend containing 40% starch ester with 12% compatibilizer showed maximum tensile strength. Thermogravimetric and differential scanning colorimetric analyses has been done for the blends, and the neat PS and the glass transition temperature of the blend has been obtained at 327 K. The water absorbency of the blends showed an increase with the increase in loading of Stph and a reduction with the addition of compatibilizer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Understanding the impact of gamma irradiation on electrical and mechanical properties of epoxy nanocomposites
Authors: Karpagam R. , Sarathi R. , Tanaka Toshikatsu
Published: December 2011

In this work, the influences of gamma irradiation on the electrical and mechanical properties of the epoxy nanocomposites were studied. The exfoliation characteristics of epoxy nanocomposite material analyzed through TEM studies. It is shown that the impact and flexural strength of the material is high with epoxy nanocomposites and gets reduced with the gamma‐irradiated specimen. The AC breakdown strength of the epoxy nanocomposites is high compared with the base epoxy resin. It is also observed that a reduction in permittivity and tan(δ) of epoxy resin added with 1 wt % of nanoclay. Increase in percentage of clay shows increase in permittivity and tan(δ). Gamma irradiation of epoxy nanocomposite material shows increase in permittivity. The volume resistivity of the material is high with epoxy nanocomposite and is less with gamma‐irradiated specimen compared with virgin specimen. The impact strength and flexural strength indicates correlation with breakdown strength of the material. It is observed that the increase in applied voltage shows an increase in magnitude of the charge density in the insulation structure. With the gamma‐irradiated specimen, the charge density (for the applied electric field) is less compared with the virgin specimen. Electric field analysis indicates that the electric field is uniform in the bulk volume of the epoxy nanocomposite material. The rate of charge decay is high with gamma‐irradiated specimen compared with virgin specimen. It is realized that material with lower resistivity has faster decay of stored charge. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Trial of early aggressive therapy in polyarticular juvenile idiopathic arthritis
Authors: Wallace Carol A. , Giannini Edward H. , Spalding Steven J. , Hashkes Philip J. , O'Neil Kathleen M. , Zeft Andrew S. , Szer Ilona S. , Ringold Sarah , Brunner Hermine I. , Schanberg Laura E. , Sundel Robert P. , Milojevic Diana , Punaro Marilynn G. , Chira Peter , Gottlieb Beth S. , Higgins Gloria C. , Ilowite Norman T. , Kimura Yukiko , Hamilton Stephanie , Johnson Anne , Huang Bin , Lovell Daniel J. ,   for the Childhood Arthritis and Rheumatology Research Alliance
Published: December 2011

Objective

To determine whether aggressive treatment initiated early in the course of rheumatoid factor (RF)–positive or RF‐negative polyarticular juvenile idiopathic arthritis (JIA) can induce clinical inactive disease within 6 months.

Methods

Between May 2007 and October 2010, a multicenter, prospective, randomized, double‐blind, placebo‐controlled trial of 2 aggressive treatments was conducted in 85 children ages 2–16 years with polyarticular JIA of <12 months' duration. Patients received either methotrexate (MTX) 0.5 mg/kg/week (maximum 40 mg) subcutaneously, etanercept 0.8 mg/kg/week (maximum 50 mg), and prednisolone 0.5 mg/kg/day (maximum 60 mg) tapered to 0 by 17 weeks (arm 1), or MTX (same dosage as arm 1), etanercept placebo, and prednisolone placebo (arm 2). The primary outcome measure was clinical inactive disease at 6 months. An exploratory phase determined the rate of clinical remission on medication (6 months of continuous clinical inactive disease) at 12 months.

Results

By 6 months, clinical inactive disease had been achieved in 17 (40%) of 42 patients in arm 1 and 10 (23%) of 43 patients in arm 2 (χ2 = 2.91, P = 0.088). After 12 months, clinical remission on medication was achieved in 9 patients in arm 1 and 3 patients in arm 2 (P = 0.053). There were no significant interarm differences in adverse events.

Conclusion

Although this study did not meet its primary end point, early aggressive therapy in this cohort of children with recent‐onset polyarticular JIA resulted in clinical inactive disease by 6 months and clinical remission on medication within 12 months of treatment in substantial proportions of patients in both arms.
Seeking Hidden Magnetic Phenomena by Theoretical Means in a Thiooxoverdazyl Adduct
Authors: Vérot Martin , Bréfuel Nicolas , Pécaut Jacques , Train Cyrille , Robert Vincent
Published: December 2011

The oxidation of 1,5‐dimethyl‐3‐(2′‐pyridyl)‐6‐thiooxotetrazane (SvdH3py) by benzoquinone leads to a 1:1 adduct of 1,5‐dimethyl‐3‐(2′‐pyridyl)‐6‐thiooxoverdazyl radical (Svdpy) with hydroquinone (hq). The single‐crystal X‐ray diffraction of this adduct at room temperature (RT) shows that the radicals exhibit a slight curvature that leads to the formation of alternating head‐to‐tail (antiparallel) stacked 1D chains. Moreover, temperature‐dependent X‐ray measurements at 100, 200, and 303 K reveal that the lateral slippages between the radicals of the stacks |δ1| and |δ2| vary from 0.64 to 0.78 Å and 0.54 to 0.40 Å between 100 and 303 K. Despite the alternation of the inter‐radical distances and lateral slippages, the magnetic susceptibility data can be fitted with excellent agreement using a regular one‐dimensional antiferromagnetic chain model with J=−5.9 cm−1. Wavefunction‐based calculations indicate an alternation of the magnetic interaction parameters correlated with the structural analysis at RT. Moreover, they demonstrate that the thermal slippage of the radicals induces a switching of the physical behavior, since the exchange interaction changes from antiferromagnetic (−0.9 cm−1) at 100 K to ferromagnetic (1.4 cm−1) at 303 K. The theoretical approach thus reveals a much richer magnetic behavior than the analysis of the magnetic susceptibility data and ultimately questions the relevance of a spin‐coupled picture based on temperature‐independent parameters.
Redefining institutional priorities
Authors: Kelly J. Terence
Published: December 2011

This chapter offers time‐tested advice for new presidents, including how to build and maintain strong relationships with trustees, how to address the persistent concerns of student success and remediation, and how to access the college's economic condition as well as how to oversee and maintain strong funding channels.
Increased enrollment + student success – funding = ?
Authors: Tschechtelin James D.
Published: December 2011

The current economic, social, and political climate presents such an unprecedented threat to the mission of community colleges that only radical changes will ensure a future in which their quality and purpose are maintained. This chapter offers a framework for how presidents and boards can meet the urgent need of staying true to the college's mission in the face of emerging fiscal and educational crises.
Leadership: A balancing act
Authors: Hines Thomas E.
Published: December 2011

This chapter explores what being a leader at the community college means, what the threats are to effective leadership, and what factors leaders should be especially concerned with as colleges face new challenges and demands. Several key ideas about leadership are presented.
Organization of the enantiomeric and racemic forms of an amphiphilic resorcinol derivative at the air–water and graphite–1‐phenyloctane interfaces
Authors: Iavicoli Patrizia , XU Hong , Keszthelyi TamáS , Telegdi Judit , WURST Klaus , Van Averbeke Bernard , Saletra Wojciech J. , Minoia Andrea , Beljonne David , Lazzaroni Roberto , De Feyter Steven , Amabilino David B.
Published: December 2011

This article describes a study of the outcome of racemate condensation in different types of monolayers. The study was performed on a resorcinol surfactant bearing an octadecyl chain and a lactate group which formed a monolayer at the interface of graphite and 1‐phenyloctane as well as a Langmuir film at the air–water interface. Control experiments with the enantiopure materials provided the characteristics of the chiral organizations. The results obtained on the racemate show that on graphite the molecule forms chiral domains, indicating that spontaneous resolution takes place at the surface, a phenomenon that has been rationalized using molecular modeling. The X‐ray crystal structure of the DMSO solvate of one of the enantiomers shows a similar type of packing to this monolayer. On the other hand, in the Langmuir layer it appears that the formation of a racemic compound is favoured, as it is in the solid state in three dimensions. The work shows how the symmetry restrictions in different environments can have a critical influence on the outcome of racemate organization, and underline the tendency of graphite to favour symmetry breaking in monolayers formed at its surface. Chirality, 2012. © 2011 Wiley Periodicals, Inc.
Characterization and Quantification of Gas Flow Distributions
Authors: Stemich Carsten , Spiegel Lothar
Published: December 2011

Für eine realistische Beurteilung von beliebigen Verteilungen müssen sowohl die Fluktuationen innerhalb des Strömungsfeldes als auch deren räumliche Verteilung berücksichtigt werden. Daher muss eine Kennzahl, die die Qualität von Verteilungen beschreibt, beides berücksichtigen. Der Variationskoeffizient beschreibt den Effekt der Fluktuationen, allerdings gehen sämtliche örtliche Informationen verloren. Es wurde eine ergänzende Kennzahl entwickelt, die beide Eigenschaften der Verteilung berücksichtigt – die Stärke der Fluktuationen sowie deren örtliche Verteilung. Die neue Methode wurde erfolgreich auf die Gasverteilung innerhalb einer Destillationskolonne mit großem Durchmesser angewendet.
Effect of drainage height on concentration‐dependent propane dispersion in vapex
Authors: Abukhalifeh Hadil , Upreti Simant Ranjan , Lohi Ali
Published: December 2011

This article examines the effect of drainage height (i.e. height of saturated porous medium) on concentration‐dependent dispersion coefficient of propane in vapour extraction (Vapex) of heavy oil. For this purpose, Vapex experiments are carried out at 21°C using propane as a solvent at 0.689 MPa pressure for three different drainage heights of the heavy oil medium. Subsequently, the concentration‐dependent dispersion coefficients of propane are determined. The results show that the dispersion coefficient of propane (at all concentrations) in heavy oil increases with the drainage height. © 2011 Canadian Society for Chemical Engineering
Ionic Conductivity of Pure Water in Charged Porous Matrix
Authors: Wang Qiang , Cha Chuan‐Sin , Lu Juntao , Zhuang Lin
Published: December 2011

It is commonly recognized that the ionic conductivity of pure water is very poor because of very low ionic concentrations. However, this work indicates that pure water in charged porous matrixes can be moderately conductive because of the ions in the electric double layer established at the solid/water interfaces. The ionic conductivity of pure water in a charged matrix changes with the electrode potential of the matrix and is influenced by the structural parameters. Both experimental measurements and theoretical calculations reveal that ionic conductivity may reach the order of 10−3 S cm−1 in commonly accessible potential region in a porous matrix made of gold nanoparticles. These results would help to understand and optimize the electrode processes in electrochemical devices without deliberately added electrolytes, such as polymer electrolyte membrane fuel cells.
Absorption, Luminescence, and Sizing of Organic Dye Nanoparticles and of Patterns Formed Upon Dewetting
Authors: Gaiduk Alexander , Yorulmaz Mustafa , Ishow Eléna , Orrit Michel
Published: December 2011

Organic nanoparticles made of a push–pull triarylamine dye with an average diameter of 60 nm, were prepared by reprecipitation. We study their photophysical properties by a combination of photothermal and fluorescence microscopy. Photothermal contrast provides a quantitative measure of the number of absorbers. The size of nanoparticles estimated from the absorption measurements was compared with sizes measured by AFM. Fluorescence and absorption microscopy provide quantum yield on the single‐particle level as a function of excitation intensity. The quantum yield strongly decreases at high intensities because of singlet–singlet or singlet–triplet annihilation. We also report the formation of molecular thin layers and of labyrinth‐shaped structures on glass substrates, presumably induced by dewetting.
Langmuir–Blodgett Films of Hexamolybdate and Naphthylamine Prepared by Two Different Approaches: Synthesis, Characterization, and Materials Properties
Authors: Liu Qian , Hu Lei , Fu Hui , Yang Jun , Fu Qiao‐Min , Liu Li , Liu Shi‐Zhong , Du Zu‐Liang , Ho Cheuk‐Lam , Dai Feng‐Rong , Wong Wai‐Yeung
Published: December 2011

Two novel covalently‐linked organic‐inorganic hybrid compounds [(n‐C4H9)4N]2[Mo6O18{≡N–(2‐Np)}] (NA–Mo6) and [(n‐C4H9)4N]2[Mo6O17{≡N–(1‐Np)}2] (NA2–Mo6) (2‐Np = 2‐naphthyl; 1‐Np = 1‐naphthyl) have been prepared by the reaction of 2‐naphthylamine (2‐NpNH2) or 1‐naphthylamine (1‐NpNH2) with [(n‐C4H9)4N]2[Mo6O19] (Mo6) in the presence of N,N′‐dicyclohexylcarbodiimide (DCC) in anhydrous acetonitrile, and have been characterized by 1H NMR, IR, UV/Vis, and fluorescence spectra as well as X‐ray crystallography. Structural analyses reveal the formation of self‐assembled infinite 1‐D and 3‐D supramolecular frameworks. The UV/Vis spectra of NA–Mo6 and NA2–Mo6 show that the lowest energy electronic transfers occur at 362 and 394 nm, respectively, which are dramatically red‐shifted when compared to that of Mo6. The luminescence studies show that Mo6 can notably quench the emission of naphthylamine. Monolayer and multilayer films of NA–Mo6 and NA2–Mo6 were fabricated on different substrates by the Langmuir–Blodgett (LB) technique using H2O as the subphase. For comparison, another two types of organic‐inorganic hybrid films composed of noncovalently‐linked 1‐NpNH2/Mo6 and 2‐NpNH2/Mo6 systems were also deposited onto the same substrates under the same conditions by the LB technique using an aqueous solution of Mo6 as the subphase. The as‐prepared organic‐inorganic hybrid films were characterized by π‐A isotherms, UV/Vis absorption spectra, photoluminescence spectra, and scanning tunneling microscopy. The results indicate that stable monolayers can be formed at the air–water interface for NA–Mo6 and NA2–Mo6, and at the air–Mo6 solution interface for 1‐NpNH2 and 2‐NpNH2. The four LB films containing NA–Mo6, NA2–Mo6, 1‐NpNH2/Mo6, and 2‐NpNH2/Mo6 display interesting electrical conductivity.
Tethered Aminohydroxylation Reaction and Its Application to Total Synthesis
Authors: Donohoe Timothy J. , Callens Cedric K. A. , Lacy Adam R. , Winter Christian
Published: December 2011

This review highlights key aspects of the Tethered Aminohydroxylation from its discovery to its current incarnation, which employs N,O‐acylated derivatives as reoxidants for osmium. The potential and generality of this reaction has been demonstrated by its application in the synthesis of several natural products.
MODELLING MULTIPLE LAND‐ AND WATER‐USE SCENARIOS FOR THREE TYPICAL PILOT AREAS IN CRIMEA, UKRAINE
Authors: Hoffmann M. , Zhovtonog O. , Bolkina O. , Mikhaylenko S.
Published: December 2011

The use of Geographic Information System (GIS) models for water quantity and quality modelling is indispensable for the determination of impacts of land‐use or climate changes that are expected to take place.

Southern Ukraine today suffers from severe droughts, floods and soil salinisation. It is therefore of utmost importance to use the available water resources optimally and to avoid loads from coastal waters.

The paper reports the results of studies that were carried out in three pilot areas in Crimea, including the catchments of the Salgir and Pobednaya rivers. The main problems of the Upper Salgir sub‐basin are related to erosion and urbanisation impacts. The transfer zone and coastal areas are subject to intensive restructuring and agricultural development, including the reconstruction and reorganisation of irrigation systems. The River Pobednaya drains a coastal area in the north‐east of Crimea. Here, irrigation and drainage and in addition waste water discharges are having impacts on the Sivash Wetlands that increasingly cover the coastal area of the Sea of Azov.

In order to solve all these problems, regional stakeholders have been invited to develop scenarios that are further evaluated by modelling exercises. Copyright © 2011 John Wiley & Sons, Ltd.
INTEGRATED LAND USE AND WATER MANAGEMENT
Authors: Barker Ian , Turner Amanda
Published: December 2011

Water in parts of England is already under significant pressure. In a world of growing pressures from climate change, increasing population and concerns over energy and food security, the competing demands on land and water will only increase in the future.

A combination of catchment flood management plans, and other catchment‐based planning, together with development of river basin management plans, have enabled good progress in advancing catchment‐scale management of land and water. However, successful protection of the environment, management of flood risk and diffuse pollution and ensuring security of water for use into the future depend on greater integration of all the activities involved in management of the land and water. An integrated planning framework looking to the longer term, providing comprehensive and cross‐cutting actions, is necessary to maximise environmental gains, protect ecosystems, and the services they provide to society.

In particular, in low‐lying areas of England, the suite of land and water management and planning frameworks set out the long‐term delivery actions required to deliver sustainable flood risk management, and improvements to water quality and resources.

These management frameworks are complemented by good land, soil and nutrient management to deliver an integrated catchment management approach resulting in multiple benefits for the environment and society, as well as ensuring that water and land are resilient to climate change and able to meet growing demands. Copyright © 2011 John Wiley & Sons, Ltd.
SPACES, ACTORS AND NEW RIVERINE ETHICS ON THE EMS
Authors: Disco Cornelis
Published: December 2011

The Ems estuary extends from just upstream of the German port of Emden to the North Sea. It is a network of tidal channels through the sand banks of the Wadden Sea and includes a contested border between Germany and the Netherlands.

The estuary is the seaway for Emden and the Dutch port of Delfzijl. It was and is the object of intensive nautical management which, despite the border tensions, generally ensured progress and mutual economic benefit. A 1960 treaty on nautical cooperation formalized this bilateral commitment to economic growth.

This paper focuses on the shift from economic development to ecological cooperation in the Ems estuary starting in the 1970s. While in the 1960s, for example, the Dutch had no qualms about disposing vast quantities of untreated industrial effluents into the Dollart, by 1979 they were arguing that plans to expand the port of Emden would disrupt the Dollart's fragile economy. As part of the growing ‘ecological web’ of international and European treaties, and thanks to the hard work of local and national environmentalist groups, the Ems estuary became the object of its own bilateral ecological agreement in 1996. Copyright © 2011 John Wiley & Sons, Ltd.
FLOOD RISKS IN CONSEQUENCE OF AGRARIAN LAND‐USE MEASURES IN FLOOD FORMATION AND INUNDATION ZONES AND CONCLUSIONS FOR FLOOD RISK MANAGEMENT PLANS
Authors: Quast Joachim , Böhme Michael , Ehlert Volker , Ette Juliane , Gottschick Manuel , Jaeckel Anette , Knierim Andrea , Messal Hilmar , Sawicka Magdalena , Sbjeschni André , Schmidt Walter , Szerencsits Manfred , Tümpling Wolf Von
Published: December 2011

The role of agricultural land use and its contribution to flood risks were the focus of the research project MinHorLam. Schematised models were applied to assess the impacts of different farming practices or of land use patterns on runoff formation as well as on water levels and flow velocities in flood conditions. The results show the range, potentials and limits of agricultural measures to mitigate flood risks. Aspects of matter accumulation in floodplains and management options were presented from case study results related to extreme flood events.

Empirical social research on farmers' and administrators' perspectives complemented the analyses. Institutional actors from water management and agriculture rated agriculture as playing a moderate to low role in causing flood events. Also hazards caused by floods or heavy rain are usually of minor importance in farmers' managerial decisions if there is no immediate risk or damage. Nevertheless, to enhance risk prevention in agriculture, more action is needed, especially cooperation among different institutional actors in flood risk management and agriculture. Copyright © 2011 John Wiley & Sons, Ltd.
DELTAS FOR THE FUTURE: LESSONS LEARNED FROM A WATER INNOVATION PROGRAMME
Authors: van der Duin Patrick , Sule Maya , Bruggeman Willem
Published: December 2011

Delta regions worldwide have to cope with increasing pressure on land use and the consequences of climate change and rising sea levels. Because existing approaches and solutions are no longer sufficient to face future challenges of flood protection, sustainable energy and freshwater supply, truly innovative approaches and technologies have to be developed and implemented. To that end, Rijkswaterstaat (NL), in collaboration with Deltares, executed a water innovation programme (WINN) in the period 2002–2010.

By analysing a selection of the important and interesting results of the WINN programme with the support of the cyclic innovation model (CIM), the aim of this paper is to identify key factors for successful innovation and provide recommendations for effective organization of a government water innovation programme. Copyright © 2011 John Wiley & Sons, Ltd.
CAN WE SAVE THE CALIFORNIA DELTA IN THE FACE OF SEA LEVEL RISE?
Authors: Roos Maurice , De Vries Johannes J.
Published: December 2011

Sea level rise would profoundly affect low‐lying coastal and estuary regions of the world and especially the Sacramento–San Joaquin delta in California. This delta, the largest on the west coast of the US, has about 120 000 ha below sea level, protected by levees, many on weak peat soil. The delta is also the hub of water transfer from north to south for two big water projects, which are vulnerable to ocean saltwater intrusion.

Sea level has been rising slowly and is projected to rise more in the next 100 years. This, coupled with continued subsidence, will make it more difficult to protect low‐lying delta lands from inundation. The biggest threat is during high water storm events, but also a few summer dry season breaks have affected water exports.

Since current rates of ocean rise are slow, a modest continuing effort in levee strengthening to handle a rise of 0.3 to 0.5 cm yr‾¹ could maintain present levels of flood protection for decades. Eventually hard choices will have to be made on which islands to save as costs rise and with better estimates of ocean rise. More than farmland is involved; much infrastructure, such as roads and pipelines, is as well. Copyright © 2011 John Wiley & Sons, Ltd.