bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and antibacterial screening of new 4‐((5‐(difluoromethoxy)‐1H‐benzo[d]imidazol‐2‐ylthio)methyl)tetrazolo[1,5‐a]quinoline derivatives
Authors: Sonar Swapnil S. , Sadaphal Sandip A. , Pokalwar Rajkumar U. , Shingate Bapurao B. , Shingare Murlidhar S.
Published: March 2010

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A method for the synthesis of previously unknown heterocyclic systems 4‐((5‐(difluoromethoxy)‐1H‐benzo[d]imidazol‐2‐ylthio)methyl)tetrazolo[1,5‐a]quinolines derivatives 6 has been developed based on various substitutes 2‐chloroquinoline‐3‐carbaldehydes 1 via the consecutive steps of conversion into tetrazolo[1,5‐a]quinoline‐4‐carbaldehyde 2 on treatment with sodium azide which upon reduction to the corresponding alcohol derivatives 3, conversion to chlorides 4 with thionyl chloride followed by the coupling with 5‐(difluoromethoxy)‐1H‐benzo[d]imidazole‐2‐thiol 5. The synthesized titled compounds (6a, 6b, 6c, 6d, 6e) were screened for the antibacterial activity against gram positive and gram negative bacteria. J. Heterocyclic Chem., (2010).
The Nonlinear trend of runoff and its response to climate change in the Aksu River, western China
Authors: Xu Jianhua , Chen Yaning , Lu Feng , Li Weihong , Zhang Lijun , Hong Yulian
Published: March 2010

The nonlinear trend of runoff and its response to climate change in the Aksu River were identified and evaluated using several selected methods, including grey relation analysis, wavelet analysis, and regression analysis. The time series of runoff and related climate variables from two hydrologic stations and four meteorological stations during 1959–2005 for the Aksu River were used to construct and test empirical models. The key findings of this study indicate that although the time series of the runoff, temperature and precipitation present nonlinear trends, the runoff exhibits a linear correlation with the temperature and precipitation. These results reveal that there is a close relationship between variations in the annual runoff of the Aksu River and regional climate change; in other words, the nonlinear trends of the variations in the runoff is the response to that of regional climate change. The details supporting the key findings are as follows: (1) The annual runoff presented nonlinear trends that depend on time scales, which appeared to have resulted from the regional climate changes that occurred during the study period. (2) The periodicity of changes in runoff, temperature, and precipitation are closely correlated, that of annual runoff occurred on 24‐year cycle, whereas annual average temperature and annual precipitation occurred on 23‐ and 25‐year cycles. (3) The annual runoff exhibited a significant, positive correlation with the temperature and precipitation at the 1‐, 2‐, 4‐, and 8‐year temporal scales. Copyright © 2010 Royal Meteorological Society
Vibrational spectroscopy of alkaline tungsten oxyfluoride crystals: structure, lattice dynamics, ordering processes, and phase transitions
Authors: Vtyurin A. N. , Gerasimova Ju. V. , Krylov A. S. , Ivanenko A. A. , Shestakov N. P. , Laptash N. M. , Voyt E. I.
Published: March 2010

Raman scattering (RS) and infrared absorption (IR) of ammonium oxyfluoride crystals (NH4)3WO3F3, (NH4)2KWO3F3, and Cs2(NH4)WO3F3are compared. Conformation of the WO3F3 octahedral groups has been established; anomalies have been found close to the transition temperatures in the internal vibrational regions of ammonium and WO3F3 groups. The phase transition in (NH4)3WO3F3 is associated mostly with the ordering of octahedral groups and formation of WO···HN hydrogen bonds. In (NH4)2KWO3F3 crystal, the transition is not related to the ordering processes; Cs2(NH4)WO3F3 retains its disordered structure down to 10 K. Copyright © 2010 John Wiley & Sons, Ltd.
Peripheral olfactory sensitivity in rodents after treatment with docetaxel
Authors: Faure Frédéric , Da Silva Stéphanie Veloso , Jakob Ingrid , Pasquis Bruno , Sicard Gilles
Published: March 2010

Objectives/Hypothesis:

Clinical studies have documented that cytotoxic chemotherapy is often associated with body weight loss and decreased enjoyment of food. Besides taste, olfaction plays a role in food intake. We assessed whether systemic chemotherapeutic cancer treatment compromises olfactory function in rats and mice treated with docetaxel (Taxotere; Sanofi‐Aventis, Paris, France).

Study Design:

Randomized, controlled trials on mice and rats.

Methods:

Male mice received a single and male rats either a single, two, or three docetaxel administrations. Olfactory function was tested by means of electroolfactograms (EOGs) from the chemosensory epithelium of the nasal septum and the endoturbinates. We evaluated and compared the magnitude of EOG responses evoked by different odorants recorded at different time points after treatment.

Results:

In both animal species, docetaxel administration reduced body weight gain, thus evidencing the general toxic effect of the drug. In both animal species, the olfactory mucosa remained responsive to stimulation of odorants during the whole course of experiment, but treatment revealed regional differences of docetaxel susceptibility and induced marked transitory electrophysiological changes. In mice and rats a significant transitory decrease in EOG response magnitude occurred after a single administration. Unexpectedly, in rats we also observed an increase of the olfactory response following the second administration of the drug.

Conclusions:

Docetaxel exerts a neurotoxic effect on olfactory epithelia of rodents at doses similar to human doses, thus inducing transitory functional alterations. Although moderate, they are consistent with the hypothesis of a dysfunction of olfactory function. Further experiments are needed to elucidate the origin of the electrophysiological effects and their impact on the olfactory perception. Laryngoscope, 2010
Office‐based injection laryngoplasty in the irradiated larynx
Authors: Tirado Yamilet , Lewin Jan S. , Hutcheson Katherine A. , Kupferman Michael E.
Published: March 2010

Objectives/Hypothesis:

To review the clinical results of office‐based injection laryngoplasty with two different therapeutic materials in patients with vocal fold paralysis and history of radiation therapy to the larynx.

Study Design:

Retrospective study.

Methods:

Chart review of 11 patients who underwent office‐based injection laryngoplasty with calcium hydroxylapatite or micronized Alloderm. All patients had a history of radiation therapy to the neck, with the larynx included in the radiation field. Voice analyses, clinical outcomes, and complications were reviewed. Efficacy of the procedure was evaluated by comparing pre‐ and postinjection mean phonation time (MPT) results from voice analysis data.

Results:

A total of 15 injections were performed in 11 patients with vocal fold paralysis (one females, 10 males, mean age 62 years). Data from voice analyses before and after the procedure were available for nine injections. The MPT was significantly increased among patients undergoing the procedure (P < .05). All procedures were successful, and only one self‐limited complication was reported.

Conclusions:

Office‐based injection laryngoplasty is a safe procedure with acceptable clinical results in patients with vocal fold paralysis who have a history of radiation therapy to the larynx. Laryngoscope, 2010
Middle ear aneurysm treated with an innovative, vessel‐preserving, aneurysm‐occluding stent
Authors: Fuller Elisa , Marotta Thomas R. , Chen Joseph M. , Willinsky Robert A. , Bharatha Aditya , O'Kelly Cian , Hochman Jordan B. , Howard Peter , Wolter Nikolaus E. , Symons Sean P.
Published: March 2010

Middle ear aneurysms are rare and difficult to treat. An innovative, parent vessel‐preserving, aneurysm occlusion stent is a treatment alternative. It redirects blood flow away from the aneurysm, resulting in stasis within, and ultimate aneurysm thrombosis. Concurrent coiling is not needed with this stent, eliminating the risk of coils extruding or migrating, or acting as a nidus for infection in the middle ear. We review a successful treatment using this device. Laryngoscope, 2010
Modified vertical dome division technique for rhinoplasty in Asian patients
Authors: Yu Myeong Sang , Jang Yong Ju
Published: March 2010

Objectives/Hypothesis:

Vertical dome division (VDD) is a useful nasal tip surgery technique. However, it is associated with postoperative complications and has never been studied in Asian patients. This study examined results following application of our modified VDD approach in Asian patients requiring nasal tip surgery.

Study Design:

A retrospective clinical chart review.

Methods:

We retrospectively studied 37 patients who underwent rhinoplasty using our modified VDD procedure. The indications were thick tip skin and relatively strong and well‐developed lower lateral cartilages. Outcome measurements were made using preoperative and postoperative photographs. Doctors and patients separately indicated satisfaction using a visual analogue scale (from 1 = satisfied, to 4 = dissatisfied).

Results:

Following surgery, the mean tip projection increment across the population was 15.8%, and the nasofrontal and nasolabial angle increments were 1.4° and 5.5°, respectively. Doctor and patient satisfaction scores were 1.54 ± 0.76 and 1.61 ± 0.81, respectively. Most patients showed prominent tip projection and good cosmetic results. Two patients (5.4%) were dissatisfied, one due to a narrow tip and the other due to nostril asymmetry.

Conclusions:

The modified VDD was an effective method for nasal tip projection and rotation in selected Asian patients. Laryngoscope, 2010
Effect of nano Al (Scx−1Zrx) precipitates on the mechanical and corrosion behavior of Al‐2.5 Mg alloys
Authors: Ahmad Z. , Aleem B. J. Abdul
Published: March 2010

Microanalytical, mechanical, and corrosion studies were undertaken to investigate the effect of nano‐precipitates of Al(Scx−1Zrx) on the mechanical and corrosion characteristics of Al 2.5 alloy containing 0, 0.15, 0.3, 0.6, and 0.9 wt% of Sc with 0.15 wt% Zr. Addition of 0.3% Sc significantly increased the yield strength due to small precipitates sizes (5–19 nm) and the high coherency of the nano‐particles. Largest contributor to the strength was grain boundary strengthening caused by pinning of grain boundary precipitates. The alloys showed a good resistance to corrosion in 3.5 wt% neutral chloride solution. The alloy offered a high passivation tendency because of homogeneous coherent nano Al(Scx−1Zrx) precipitates. The nano precipitates interfaces and homogeneously distributed Al3Sc precipitates offer a high degree of corrosion resistance to Al 2.5 Mg Sc alloys compared to conventional aluminum alloys, such as Al 6061 and Al6013.
Correlation of content and corrosion protection of volatile corrosion inhibitors in packaging material – regaining trust in VCI
Authors: Eibl S. , Reiner D.
Published: March 2010

Two representative types of commercial volatile corrosion inhibitor (VCI) packaging materials without a potential for health hazards according to TRGS 615 were investigated: a paper containing ethanol amine and a polyethylene foil containing sodium nitrite as main VCI ingredients. For a variation of VCI concentration the packaging material was thermally treated at 60–100 °C and the amount of VCI remaining was determined after this accelerated desorption. Additionally a nitrite‐free polyethylene foil was impregnated with various amounts of sodium nitrite. Correlations of VCI content – of both the amine and nitrite – with corrosion protection of mild steel were observed. For ethanol amine a color change reaction is proposed to indicate the remaining potential of corrosion protection. This work is aimed at regaining trust in VCI technology.
Influence of Carbon Nanofiber Network Variability on the AC Conductivity of Polyetherimide Composite Films
Authors: Li Bin , Zhong Wei‐Hong
Published: March 2010

A pronounced and distinctive increase in the conductivity of polyetherimide nanocomposite films containing CNF agglomerates is reported. It is demonstrated that a variation of the CNF network can have a dramatic effect on the AC conductivity of PEI composites. The effect is found in composites containing relatively large and strongly entangled CNF agglomerates, and it is suggested that is is due to a new mechanism of electrical conduction. The observed behavior may reveal the distinctive response of electrons in strongly entangled CNF networks in polymer films to an AC field in contrast to a DC field, and could also result in a negative dielectric response.

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A Possible Means to Assist the Processing of PET, PTT and PBT
Authors: Alessi Matteo , Conzatti Lucia , Hodge Philip , Taglialatela Scafati Santolo , Stagnaro Paola
Published: March 2010

Blends of PET, PTT and PBT with the corresponding MCOs have lower melt viscosities than the pure polymers. This effect of MCOs on viscosity has the potential for exploitation in polymer fabrication and especially in the processing of composite materials. Thus, the blends can be more easily melt‐processed than the pure polymers, and the MCOs can then subsequently be converted in situ into high‐molar‐mass polymers by ED‐ROPs. No catalyst is needed for the ED‐ROPs. It was shown that suitable polymer/MCO blends can be obtained directly by carrying out cyclo‐depolymerizations at appropriate concentrations. Suitable polymer/MCO blends can also, almost certainly, be obtained by carrying out the original polyester syntheses at lower concentrations than normally used.

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Interpenetrating Polymer Networks of Hydrocarbon and Fluorocarbon Polymers: Epoxy/Fluorinated Acrylic Macromonomers
Authors: Sangermano Marco , Carbonaro William , Bongiovanni Roberta , Thomas Richard R. , Kausch Charles M.
Published: March 2010

A fluorinated acrylic resin was synthesized for use as a co‐monomer with a commercially available epoxy resin for UV‐cured interpenetrating polymer network preparation. Hybrid IPN networks were achieved with morphology ranging from a co‐continuous IPN to complete phase separation simply by changing monomer ratios. Highly hydrophobic coatings with good adhesion properties on glass substrates were obtained.

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Induced Crystallization of PLLA in the Presence of 1,3,5‐Benzenetricarboxylamide Derivatives as Nucleators: Preparation of Haze‐Free Crystalline PLLA Materials
Authors: Nakajima Hajime , Takahashi Masahiko , Kimura Yoshiharu
Published: March 2010

The crystallization behavior of poly(L‐lactide) (PLLA) was investigated in the presence of benzenetricarboxylamide (BTA) derivatives as crystal nucleators. BTA‐cyclohexyl (BTA‐cHe) was the most effective nucleating agent, but induced a complete loss of transparency of the processed material. On the other hand, BTA‐n‐hexyl (BTA‐nHe) enhanced crystallization with little increase in haze. PLLA containing BTA‐cHe enhanced PLLA crystallization in α‐form crystal whereas BTA‐nHe enhanced α′‐form (incomplete α‐form) with forming smaller spherulites. TEM revealed BTA‐nHe had completely dissolved in the PLLA matrix in melt and recrystallized during the thermal annealing process. It was also found that the size of the recrystallized BTA‐nHe was in the nanometer range to effectively nucleate the PLLA crystals.

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Facile Synthesis of Glycopolypeptides by Combination of Ring‐Opening Polymerization of an Alkyne‐Substituted N‐carboxyanhydride and Click “Glycosylation”
Authors: Xiao Chunsheng , Zhao Changwen , He Pan , Tang Zhaohui , Chen Xuesi , Jing Xiabin
Published: March 2010

Synthetic glycopolypeptides have attracted much interest for application in biomedical field as they are structural mimics to the natural glycopeptides or glycoproteins. However, the synthesis methods toward glycopolypeptides are still few or less efficient. Herein, we present a facile route to preparation of glycopolypeptides with highly effective “glycosylation” by click postpolymerization modification. First, an alkyne‐substituted N‐carboxyanhydride (NCA) monomer was synthesized and subsequently polymerized to afford the polypeptide with “clickable” alkyne pendants. The alkyne‐functionalized polypeptide was then “glycosylated” by click reaction of different sugar azides to the alkyne pendants with high efficiency. All the obtained glycopolypeptides were soluble and preferred α‐helix conformation in water. Primary studies on the obtained glycopolypeptides binding with Con A lectin were assessed by turbidimetric assay. The more quantitive studies of the interactions between lectin proteins and the synthetic glycopolypeptides, and the application of these materials as the multivalent ligands are in progress.

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Supramolecular Star‐Shaped Poly(ethylene glycol) Based on a [2 × 2] Grid‐Like Metal Complex
Authors: Hoogenboom Richard , Moore Brian C. , Schubert Ulrich S.
Published: March 2010

Supramolecular star‐shaped polymers are a class of materials that are formed by self‐assembly of polymeric precursors. The resulting structures combine the beneficial properties of conventional star‐shaped polymers and (reversible) supramolecular interactions. We previously introduced [2 × 2] copper(I) grids of 3,6‐di(2‐pyridyl)‐pyridazine (DPP) as structural motif to form the core of supramolecular star‐shaped polymers. In the current work, this concept is expanded to star‐shaped poly(ethylene glycol) (PEG) by end‐functionalization of amine‐functionalized PEG with DPP. The synthesis and characterization of PEG‐DPP as well as the self‐assembly into star‐shaped supramolecular polymers upon copper(I) complexation are discussed in detail.

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PEO‐Covered Nanoparticles by Emulsion Inversion Point (EIP) Method
Authors: Sadtler Véronique , Rondon‐Gonzalez Marianna , Acrement Audrey , Choplin Lionel , Marie Emmanuelle
Published: March 2010

This study reports the first PEO‐coated polymer nanoparticles synthesis by miniemulsion polymerization of nano‐emulsions prepared by the low‐energy emulsification method called EIP. The surfactant used was Brij 98, a PEO based non ionic commercial surfactant. The partial phase diagram of the system water/Brij 98/styrene was first determined. The Emulsion Inversion Point technique was then used on the water/Brij 98/styrene system to the formation of styrene‐in‐water nano‐emulsions. After miniemulsion polymerization, particle sizes as low as 36 nm were obtained. To the best of our knowledge, this method had not been used for polymerizable system up to now.

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Digestibility and allergenicity assessment of enzymatically crosslinked β‐casein
Authors: Stanic Dragana , Monogioudi Evanthia , Ercili Dilek , Radosavljevic Jelena , Atanaskovic‐Markovic Marina , Vuckovic Olga , Raija Lantto , Mattinen Maija , Buchert Johanna , Cirkovic Velickovic Tanja
Published: March 2010

Crosslinking enzymes are frequently used in bioprocessing of dairy products. The aim of this study was to examine the effects of enzymatic crosslinking on IgE binding, allergenicity and digestion stability of β‐casein (CN). β‐CN was crosslinked by transglutaminase, tyrosinase, mushroom tyrosinase/caffeic acid and laccase/caffeic acid. The IgE binding to β‐CN was compared in vitro by CAP inhibition assay, ELISA inhibition as well as ex vivo by basophil activation assay. Crosslinked CNs were digested by simulated gastric fluid for 15 and 60 min and obtained digests analyzed for their ability to inhibit IgE binding by CAP inhibition assay and SDS‐PAGE. The ability of crosslinked CNs to activate basophils was significantly reduced in seven patients in the case of CN crosslinked by laccase and moderately reduced in the case of tyrosinase/caffeic acid crosslinked CN (in two cow's milk allergy patients tested with different allergen concentrations). The response to various crosslinked CNs differed individually among patients' sera tested by ELISA inhibition assay. The presence of caffeic acid hampered digestion by pepsin, and this effect was most pronounced for the tyrosinase/caffeic acid crosslinked CN. The laccase/caffeic acid and mushroom tyrosinase/caffeic acid had the highest potential in mitigating IgE binding and allergenicity of the β‐CN out of all investigated enzymes. The presence of a small phenolic compound also increased digestion stability of β‐CN.
Finite element methods for quantum electrodynamics using a Helmholtz decomposition of the gauge field
Authors: Ketelsen C. , Manteuffel T. , McCormick S. , Ruge J.
Published: March 2010

The Dirac equation of quantum electrodynamics describes the interaction between electrons and photons. Large‐scale numerical simulations of the theory require repeated solution of the two‐dimensional Dirac equation, a system of two first‐order partial differential equations coupled to a background U(1) gauge field. Traditional discretizations of this system are sparse and highly structured, but contain random complex entries introduced by the background field. For even mildly disordered gauge fields, the near kernel components of the system are highly oscillatory, rendering standard multilevel methods ineffective. We consider an alternate formulation of the governing equations obtained by a transformation of the continuum operator that decouples the system into separate scalar diffusion‐like equations. We discretize the transformed system using least‐squares finite elements and use adaptive smoothed aggregation multigrid to solve the resulting linear system. We present numerical results and discuss implications of the transformed formulation in terms of the physical theory. Copyright © 2010 John Wiley & Sons, Ltd.
The role of the YMCA in the origins of U.S. nonprofit management education
Authors: Lee Mordecai
Published: March 2010

The given narrative of the origins of nonprofit management education tends to begin in the 1970s or 1980s, recognizing earlier efforts that were limited to individual professional disciplines, such as social work administration. This historical inquiry examines whether the origins of generic nonprofit management education can be traced further back. It identifies the 1911 bachelor of association science degree from the Chicago YMCA College as at least a proto‐nonprofit management degree and a 1935 text by Ordway Tead, issued by the YMCA's publishing house, as a contender for the first text in generic nonprofit management.
How might servant leadership work?
Authors: Ebener Dan R. , O'Connell David J.
Published: March 2010

This study examines the mechanics of servant leadership, particularly how it enhances organizational citizenship and how that drives organizational effectiveness. A case study of three successful Catholic parishes identified three direct leadership mechanisms—invitation, inspiration, and affection—that evoke and nurture the service of others. The case analysis also identified two organizational leadership mechanisms—culture building and structural initiatives—through which servant leaders fostered organizational citizenship. This study contributes to an understanding of organizational effectiveness by suggesting how leaders might foster the growth and development of others, build servant‐oriented organizations, and improve overall organizational performance.
Building a better workplace for teen volunteers through inclusive behaviors
Authors: Waters Richard D. , Bortree Denise Sevick
Published: March 2010

Facing a decline in the number of hours donated to nonprofit organizations, volunteer coordinators must strive to determine the most effective strategies for retaining volunteers. Relationship management theory provides a framework to gauge the well‐being of an organization's relationship with its stakeholders. Through surveys administered to 317 teenage volunteers at three library systems, this study found that of four factors—trust, commitment, satisfaction, and control mutuality—trust had the strongest ability to predict intent to continue volunteering. Further analysis revealed that trust could be enhanced by including teenagers in work groups throughout the organization, seeking their input on organizational decisions, and ensuring they receive formal and informal organizational communications.
Synthesis and microwave absorbing properties of poly(3,4‐ethylenedioxythiophene) (PEDOT) microspheres
Authors: Ni Xunwei , Hu Xiujie , Zhou Shuyun , Sun Chenghua , Bai Xiaoxia , Chen Ping
Published: March 2010

Poly(3,4‐ethylenedioxythiophene) (PEDOT) solid and hollow microspheres were successfully synthesized by simply adjusting the concentration of 3,4‐ethylenedioxythiophene (EDOT) and the molar ratio of EDOT to ammonium persulfate (APS) (represented by (EDOT)/(APS)), respectively. Microwave absorbing properties of PEDOT microspheres with tunable reflection loss (RL) and microwave frequency band were described in detail. The relationships between the conductivity and RL of PEDOT microspheres were also discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Poly(methyl methacrylate)‐coated carbonyl iron particles and their magnetorheological characteristics
Authors: Jiang Wanquan , Zhu Hong , Guo Chaoyang , Li Jianfeng , Xue Qun , Feng Jianghua , Gong Xinglong
Published: March 2010

Magnetorheological fluids (MRFs) are types of suspensions that contain magnetic particles and a carrier fluid, and are considered as semi‐active smart materials. By tuning the strength of an external magnetic field, like other traditional MRFs, a carbonyl iron (CI)–poly(methyl methacrylate) (PMMA) particle‐based MRF can change reversibly from a fluid‐like state to a solid‐like state within milliseconds. In the research reported, CI particles were encapsulated with PMMA via emulsion polymerization. After the polymerization, the fabricated CI–PMMA composite particles were dispersed in a suspension medium to prepare MRF. The synthesized CI–PMMA composite particle‐based MRF showed a shear stress of 60 kPa at the magnetic field strength of 0.6 T, and a greatly enhanced anti‐sedimentation stability. Copyright © 2010 Society of Chemical Industry
Investigation of clay modifier effects on the structure and rheology of supercritical carbon dioxide‐processed polymer nanocomposites
Authors: Bellair Robert J. , Manitiu Mihai , Gulari Esin , Kannan Rangaramanujam M.
Published: March 2010

Superior property enhancements in polymer–clay nanocomposites can be achieved if one can significantly enhance the nanoclay dispersion and polymer–clay interactions. Recent studies have shown that nanoclays can be dispersed in polymers using supercritical carbon dioxide (scCO2). However, there is need for a better understanding of how changing the clay modifier affects the clay dispersability by scCO2 and the resultant nanocomposite rheology. To address this, the polystyrene (PS)/clay nanocomposites with “weak” interaction (Cloisite 93A clay) and “strong” interaction (Cloisite 15A clay) have been prepared using the supercritical CO2 method in the presence of a co‐solvent. Transmission electron microscopy images and small‐angle X‐ray diffraction illustrate that composites using 15A and 93A clays show similar magnitude of reduction in the average tactoid size, and dispersion upon processing with scCO2. When PS and the clays are coprocessed in scCO2, the “dispersion” of clays appears to be independent of modifier or polymer–clay interaction. However, the low‐frequency storage modulus in the scCO2‐processed 15A nanocomposites is two orders of magnitude higher than that of 93A nanocomposites. It is postulated that below percolation (solution blended composites), the strength of polymer–clay interaction is not a significant contributor to rheological enhancement. In the scCO2‐processed nanocomposites the enhanced dispersion passes the percolation threshold and the interactions dictate the reinforcement potential of the clay–polymer–clay network. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 823–831, 2010
Quantitative analysis of near surfaces three‐dimensional orientation of polymer chains in PET and PEN films using polarized ATR FTIR spectroscopy
Authors: Momose Miho , Ando Shinji
Published: March 2010

Polarized attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy was utilized to characterize the three‐dimensional orientation of polymer chains near highly anisotropic surfaces generated by uniaxial drawing. A versatile method was proposed to analyze the molecular orientation of the polymers by combining the experimental refractive indices and optimized contact pressure by an anvil for solving the optical contact problem. This method is effective even when changes in the molecular orientation along the thickness direction caused by drawing are remarkable. In addition, this method enables quantitative comparison of the molecular orientation among different polymers in the same coordinate system. From the molecular orientation analysis of poly (ethylene terephthalate) (PET) and poly (ethylene naphthalate) (PEN), it was revealed that this method has a broader range of applications with high accuracy in estimating the molecular orientation of polymers compared with the conventional methods. The significant changes in the molecular orientation caused by uniaxial and biaxial drawing of PET and PEN films were quantitatively analyzed, and the reasons for the significant in‐plane orientation of PEN chains on the film plane are discussed. In addition, the difference in the molecular orientation between both sides of the films was also demonstrated. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 870–879, 2010
The structure and electric characters of proton‐conducting chitosan membranes with various ammonium salts as complexant
Authors: Du J. F. , Bai Y. , CHU W. Y. , Qiao L. J.
Published: March 2010

The structural and electric properties of chitosan electrolytes doped by three different ammonium salts [CH3COONH4, NH4Cl, and (NH4)2SO4] were discussed. The chitosan electrolytes were prepared by solution casting technique. The results show that the addition of ammonium salts leads to: The formation of complexation between ammonium salts and chitosan matrix, the destruction of crystal forms, and the enhancement of amorphous nature. With the rise of salt content, both the glass transition temperature and the activation energy show a “V”‐type trend, whereas the conductivity exhibits a reverse trend. For different ammonium salts, the electric properties of the chitosan electrolyte are different due to the Coulomb force between anion of salts and functional groups. The CH3COONH4 doped chitosan electrolyte exhibits the optimum electric properties, whereas those of (NH4)2SO4 doped chitosan electrolyte are worst. The chitosan electrolyte doped with 40 wt % CH3COONH4 has the lowest glass transition temperature of 369 K, the lowest activation energy of 0.19 eV, and the highest ionic conductivity of 2.87 × 10−4 S cm−1 at room temperature. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 880–885, 2010
Multiscale Lagrangian fluid dynamics simulation for polymeric fluid
Authors: Murashima Takahiro , Taniguchi Takashi
Published: March 2010

We have developed a simulation technique of multiscale Lagrangian fluid dynamics to tackle hierarchical problems relating to historical dependency of polymeric fluid. We investigate flow dynamics of dilute polymeric fluid by using the multiscale simulation approach incorporating Lagrangian particle fluid dynamics technique (the modified smoothed particle hydrodynamics) with stochastic coarse‐grained polymer simulators (the dumbbell model). We have confirmed that our approach is well in agreement with the macroscopic results obtained by a constitutive equation corresponding to the dumbbell model, and observed that microscopic thermal fluctuation appears in macroscopic fluid dynamics as dispersion phenomena. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 886–893, 2010
Effects of chain conformation and chain length on degree of aggregation in assembled particles of conjugated polymer in solvents–nonsolvent: A spectroscopic study
Authors: Traiphol Rakchart , Potai Ruttayapon , Charoenthai Nipaphat , Srikhirin Toemsak , Kerdcharoen Teerakiat , Osotchan Tanakorn
Published: March 2010

This article explores photophysical properties and aggregation behaviors of conjugated polymer, poly[2‐methoxy, 5‐(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene](MEH−PPV), in various solvent–nonsolvent systems by utilizing UV/vis absorption and photoluminescence (PL) spectroscopy. The isolated chains of MEH‐PPV dispersed in solvents including dichloromethane, chloroform, and tetrahydrofuran adopt either extended or collapsed conformations depending on local polymer–solvent interactions. Aggregation of the MEH‐PPV in these solvents is induced by addition of a poor solvent, cyclohexane. The formation of aggregates is indicated by the appearance of distinct red‐shift peaks in the absorption and PL spectra. The degree of aggregation in each solvent–nonsolvent system is compared by means of absorbance and PL intensity of the aggregate bands. In early stage of the aggregation, the amount of aggregates in system is controlled by the solubility of polymer. When the polymer chains are forced to densely pack within assembled particles by increasing ratio of cyclohexane to 99 v/v %, the conformation of individual chain plays important role. We have found that the extended chains facilitate the aggregation in the assembled particles. Increasing chain length of polymer promotes the aggregation in early stage and densely packed particles. Size distribution of the assembled particles is also found to depend on the choice of solvent. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 894–904, 2010
Ar/HMDSO/O2 Fed Atmospheric Pressure DBDs: Thin Film Deposition and GC‐MS Investigation of By‐Products
Authors: Fanelli Fiorenza , Lovascio Sara , d'Agostino Riccardo , Arefi‐Khonsari Farzaneh , Fracassi Francesco
Published: March 2010

The thin film deposition in DBDs fed with Ar/HMDSO/O2 mixtures was studied by comparing the FT‐IR spectra of the deposits with the GC‐MS analyses of the exhaust gas. Under the experimental conditions investigated, oxygen addition does not enhance the activation of the monomer while it highly influences the chemical composition and structure of the deposited coating as well as the quali‐quantitative distribution of by‐products in the exhaust. Without oxygen addition a coating with high monomer structure retention is obtained and the exhaust contains several by‐products such as silanes, silanols, and linear and cyclic siloxanes. The dimethylsiloxane unit seems to be the most important building block of oligomers. Oxygen addition to the feed is responsible for an intense reduction of the organic character of the coating as well as for a steep decrease, below the quantification limit, of the concentration of all by‐products except silanols. Some evidences induce to claim that the silanol groups contained in the deposits are formed through heterogeneous (plasma‐surface) reactions.

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Scattering of charged tensor bosons in gauge and superstring theories
Authors: Antoniadis I. , Savvidy G.
Published: March 2010

We calculate the leading‐order scattering amplitude of one vector and two tensor gauge bosons in a recently proposed non‐Abelian tensor gauge field theory and open superstring theory. The linear in momenta part of the superstring amplitude has identical Lorentz structure with the gauge theory, while its cubic in momenta part can be identified with an effective Lagrangian which is constructed using generalized non‐Abelian field strength tensors.
Bioactivity against Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) of Cymbopogon citratus and Eucalyptus citriodora essential oils grown in Colombia
Authors: Olivero‐Verbel Jesús , Nerio Luz S , Stashenko Elena E
Published: March 2010

BACKGROUND: Essential oils isolated from Cymbopogon citratus (DC) Stapf. and Eucalyptus citriodora Hook grown in Colombia were analysed by gas chromatography–mass spectrometry (GC‐MS) and tested for repellent activity and contact toxicity against Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae).

RESULTS: The main components of C. citratus oil were geranial (34.4%), neral (28.4%) and geraniol (11.5%), whereas those of E. citriodora were citronellal (40%), isopulegol (14.6%) and citronellol (13%). The mean repellent doses after 4 h exposure were 0.021 and 0.084 mL L−1 for C. citratus and E. citriodora oils respectively—values lower than that observed for the commercial product IR3535 (0.686 mL L−1).

CONCLUSION: These studies showed the composition and repellent activity of essential oils of C. citratus and E. citriodora, suggesting that these are potential candidates as insect repellents. Copyright © 2010 Society of Chemical Industry
Controlling the conductivity of InN
Authors: Van de Walle C. G. , Lyons J. L. , Janotti A.
Published: March 2010

InN has emerged as a highly promising material for a number of technological applications, but progress is still hampered by lack of control over its conductivity. The material exhibits a high tendency for unintentional n‐type conductivity, both in the bulk and on the surface. We discuss the origins of this conductivity, considering point defects, impurities, and surface states. First‐principles calculations based on density functional theory, with suitable band‐gap corrections, have been fruitfully applied to investigate doping issues. The results indicate that native point defects are unlikely to be the source of bulk conductivity and that attention should be focused on unintentional incorporation of impurities. In particular, hydrogen is a prime candidate for shallow donors in InN. Both interstitial and substitutional hydrogen have high solubility and give rise to n‐type conductivity. Substitutional hydrogen consists of H sitting on a nitrogen site, bonding equally to the four In nearest neighbors in a multicenter‐bond configuration (a highly unusual type of chemical bond). Substitutional hydrogen, somewhat counterintuitively, is a double donor. With regard to p‐type doping, Mg is a promising acceptor in InN. Its ionization energy is ∼0.2 eV and it has lower formation energy in InN than in GaN. The problems encountered in p‐type doping of InN are therefore not due to the properties of the acceptor, but to compensation by native defects or unintentional impurities acting as donors. In addition to the bulk conductivity, accumulation of electrons has been almost universally observed on InN surfaces. While donor impurities adsorbed on the surface could of course contribute to this conductivity, we have proposed that the accumulation layers are an intrinsic property of the material that can be attributed to the fact that on polar surfaces occupied surface states are located above the conduction‐band minimum (CBM). Fermi‐level pinning occurs due to occupied surface states above the CBM, for all In/N ratios, thus explaining the observed electron accumulation. Interestingly, we have found an absence of electron accumulation on nonpolar surfaces of InN at moderate In/N ratios, in agreement with experimental observations on cleaved surfaces. Consequences for growth as well as for devices will be discussed.
Effects of pressure and inter‐electrode distance on deposition of nanocrystalline silicon under high pressure conditions
Authors: Liu Yanchao , Verkerk Arjan D. , Rath Jatindra K. , Schropp Ruud E. I. , Goedheer Wim J.
Published: March 2010

Pressure (p) and inter‐electrode distance (d) are important parameters in the process of depositing hydrogenated nanocrystalline silicon (nc‐Si:H) by very high frequency plasma enhanced chemical vapour deposition (VHF PECVD). High quality nc‐Si:H materials are normally deposited at high pressure (1 mbar < p < 7 mbar). However, systematic research on the combined effects of p and d is rare. In order to optimize nc‐Si:H for solar cells, such effects are investigated for a silane‐hydrogen discharge at high pressure conditions. All nc‐Si:H layers were deposited at fixed hydrogen dilution ratio (H2/SiH4), power and frequency. With optical emission spectroscopy, direct images taken by a photo camera and by 1D SiH4/H2 plasma simulation, three different series were analyzed to study the combined effects of p and d at high pressure. The effects on the crystalline ratio and the porosity of the deposited silicon layers were also investigated. When the p ·d product is constant, the plasma sheath becomes relatively thinner when d increases. When p or d increases independently, the electron density decreases. All the above modifications can increase the deposition rate, but by different mechanisms. When nc‐Si:H is deposited at a p ·d product of 30 mbar·mm, compact material with high crystalline ratio is obtained (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PS‐NH2 + PMMA‐COOH blend: A promising substrate material for the deposition of densely packed gold nanoparticles
Authors: Božanić D. K. , Ivković M. , Bibić N. , Hegewald J. , Pionteck J. , Žikić R. , Djoković V.
Published: March 2010

Densely packed gold nanoparticles with narrow size distribution were fabricated by pulsed laser deposition using a blend of amino‐terminated polystyrene (PS‐NH2) and carboxyl‐terminated polymethylmethacrylate (PMMA‐COOH) as a deposition substrate. Transmission electron microscopy showed spherical Au nanoparticles with an average size of 5 nm. UV–vis absorption spectra of the Au/blend nanocomposite films exhibited a strong resonance band at 658 nm. The analyses of the spectrum using the effective medium Bergman theory showed that the nanocomposite is comprised of isolated and randomly arranged nanoparticles. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The essential ingredients leading to the explosive growth stage of the European wind storm Lothar of Christmas 1999
Authors: Rivière G. , Arbogast P. , Maynard K. , Joly A.
Published: March 2010

Key dynamical ingredients leading to the explosive growth stage of the extratropical wind storm Lothar (24–26 December 1999) are identified by performing numerical sensitivity experiments using the Météo‐France operational model. This stage suddenly occurred when the surface cyclone crossed the upper‐level jet in its exit region. The model is shown to capture quite well the whole process by starting the forecast 12 h before the start of the explosive growth stage.

A first set of experiments consists of revisiting the role of humidity and other physical processes. A run suppressing latent heating does not exhibit any cyclone growth, similar to a previous study by other authors. However, a frictionless dry adiabatic run, i.e. when latent heating processes and dissipation terms are both suppressed, is shown to reproduce the timing and the location of the rapid intensification stage but not its intensity (which is overestimated). Moist processes are thus crucial because they compensate for the dissipation terms, but the vertical coupling between the surface cyclone and the upper‐level jet can be reproduced and interpreted in terms of frictionless dry adiabatic interactions, at least for conceptual purposes.

All the other numerical experiments have the full physics of the model and only differ in their initial conditions. The modification of the flow is performed using a recently developed potential vorticity inversion method. Upper‐level high‐frequency anomalies are shown to have only a moderate impact on the rapid deepening of the surface cyclone. Other experiments are conducted to look at the sensitivity to the strength of the upper‐level jet, to the intensity of the low‐level baroclinicity, to the location of the jet exit and finally to the shape, amplitude and location of the low‐level cyclone. The location of the explosive growth stage depends primarily on the position of the low‐frequency jet exit while its intensity and even its existence is strongly sensitive to the low‐level background baroclinicity and to the properties of the incipient surface cyclone itself. Copyright © 2010 Royal Meteorological Society
Enhanced aerobic bioremediation of a gasohol release in a fractured bedrock aquifer
Authors: Heaston Mark S. , Hartig Leslie L. , Robinson Melissa , Woodward David S.
Published: March 2010

In January 2005, a gasoline tanker carrying approximately 8,500 gallons of gasohol (gasoline containing 10 percent ethanol) overturned and caught fire in the front yard of a residence. Emergency response crews responded to the accident, extinguished the fire, and recovered residual gasoline on the ground surface. Soil impacted by the release was then removed and disposed of off‐site and free‐phase gasohol was recovered using a combination of vacuum recovery, pumping, and bailing to the extent practicable. Following free product recovery efforts, a feasibility evaluation was completed to select a technology to address the remaining dissolved‐phase contaminants that resulted in biosparging pilot testing and, ultimately, the installation of a full‐scale biosparging system. The full‐scale system has been operating for approximately 21 months, and contaminant concentrations within the heart of the plume have decreased dramatically over a short period of time—in most cases, to below applicable cleanup standards. Despite the complex hydrogeologic conditions and significant initial concentrations, biosparging has proven to be an effective technology to remediate this gasohol release, and it is anticipated that drinking‐water standards can be achieved following two to three years of biosparging (i.e., an additional 3 to 15 months of operations). © 2010 Wiley Periodicals, Inc.
Closing the mass balance at chlorinated solvent sites: Sources and attenuation processes
Authors: Kamath Roopa , Looney Brian B. , Newell Charles J. , Adamson David T. , Vangelas Karen M.
Published: March 2010

Using detailed mass balance and simple analytical models, a spreadsheet‐based application (BioBalance) was developed to equip decision makers with a predictive tool that can provide a semiquantitative projection of source‐zone concentrations and provide insight into the long‐term behavior of the associated chlorinated solvent plume. The various models were linked in a toolkit in order to predict the composite impacts of alternative source‐zone remediation technologies and downgradient attenuation processes. Key outputs of BioBalance include estimates of maximum plume size, the time frame for plume stabilization, and an assessment of the sustainability of anaerobic natural attenuation processes. The toolkit also provides spatial and temporal projections of integrated contaminant flux and plume centerline concentrations.

Results from model runs of the toolkit indicate that, for sites trying to meet traditional, “final” remedial objectives (e.g., two to three orders of magnitude reduction in concentration with restoration to potable limits), “dispersive” mechanisms (e.g., heterogeneous flow and matrix diffusion) can extend remedial time frames and limit the benefits of source remediation in reducing plume sizes. In these cases, the removal of source mass does not result in a corresponding reduction in the time frame for source remediation or plume stabilization. However, this should not discourage practitioners from implementing source‐depletion technologies, since results from the toolkit demonstrate a variety of measurable benefits of source remediation. Model runs suggest that alternative, “intermediate” performance metrics can improve and clarify source remediation objectives and better monitor and evaluate effectiveness. Suggested intermediate performance metrics include reduction in overall concentrations or mass within the plume, reduction of flux moving within a plume, and reduction in the potential for risk to a receptor or migration of a target concentration of contaminant beyond a site boundary.

This article describes the development of two key modules of the toolkit as well as illustrates the value of using intermediate performance metrics to evaluate the performance of a source‐remediation technology. © 2010 Wiley Periodicals, Inc.