bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photopolymerization of vinyl ether networks using an iodonium initiator—The role of photosensitizers
Authors: Cook Wayne D. , Chen Shaohua , Chen Fei , Kahveci Muhammet U. , Yagci Yusuf 
Published: September 2009

AbstractPhoto‐differential scanning calorimetry (photo‐DSC) and UV‐visible spectrometry were used to investigate the photocuring kinetics of visible light initiated cationic photopolymerization of triethyleneglycol divinyl ether with a diphenyl iodonium salt and three photosensitizers, 1‐chloro‐4‐propoxy‐9H‐thioxanthen‐9‐one (CPTXO), acridine orange (AO), and camphorquinone (CQ). Although all photosensitizers were effective in causing photopolymerization, CPTXO and AO photo‐reacted during the irradiation; whereas CQ was not significantly consumed during the timescale of the photo‐DSC experiment. This difference in photo‐reactivity has not been reported previously, and indicates that the reaction of the iodonium ion with CPTXO and AO results in the formation of the photosensitizer radical cation, whereas the CQ mechanism involves the reduction of the CQ excited state to a ketyl radical by a H‐donor (monomer) followed by the oxidation of the ketyl radical by the iodonium salt and thus regeneration of the CQ. For the CPTXO and AO systems, the photopolymerization rate was retarded by a radical inhibitor but the CQ system was unaffected, which confirms that different mechanisms are involved. The cure rate was found to be proportional to the concentrations of CPTXO and CQ but appeared to follow an approximately square root dependence on the AO concentration. Mechanisms to explain these differences were presented. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5474–5487, 2009
Synthesis and optoelectronic properties of alternating benzofuran/terfluorene copolymer with stable blue emission
Authors: Zhang Haichang , Guo Erqian , Fang Yujie , Ren Peihua , Yang Wenjun 
Published: September 2009

AbstractThe solution processable alternating benzofuran/terfluorene copolymer bearing side oxadiazole groups (PBF‐OXD) was synthesized and its optoelectronic properties and color stability were investigated. Electron‐deficient and stereohindered oxadiazole units were used as pendent groups to compensate for the poor electron‐transporting ability of a p‐type polymer backbone, to depress the intermolecular π‐stacking, and to improve solubility while retaining polymer blue emission. PBF‐OXD showed a glass transition at 135 °C and an onset decomposition temperature of ∼345 °C. A simple EL device, with the configuration of ITO/PEDOT:PSS/PBF‐OXD/Ba/Al, displayed a stable blue emission (λmax = 434 nm), good color purity (full width half‐maximum = 59 nm), maximum brightness of 1400 cd/m2, and a maximum luminance efficiency of 0.95 cd/A. The PL and EL spectra changed slightly on annealing and on increasing the applied voltage. These results show that the as‐synthesized copolymer PBF‐OXD had integrated respective functions of its different building blocks and exhibited good thermal and color stability with improved EL performance. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5488–5497, 2009
Low bandgap π‐conjugated copolymers based on fused thiophenes and benzothiadiazole: Synthesis and structure‐property relationship study
Authors: Zhang Shiming , Guo Yunlong , Fan Haijun , Liu Yao , Chen Hsiang‐Yu , Yang Guanwen , Zhan Xiaowei , Liu Yunqi , Li Yongfang , Yang Yang 
Published: September 2009

AbstractA series of low bandgap conjugated polymers consisting of benzothiadiazole alternating with dithienothiophene (DTT) or dithienopyrrole (DTP) unit with or without 3‐alkylthiophene bridge have been synthesized. Effect of the fused rings and 3‐alkylthiophene bridge on the thermal, optical, electrochemical, charge transport, and photovoltaic properties of these polymers have been investigated. These polymers show broad absorption extending from 300 to 1000 nm with optical bandgaps as low as 1.2 eV; the details of which can be varied either by incorporating 3‐alkylthiophene bridge or by replacing DTT with DTP. The LUMO levels (−2.9 to −3.3 eV) are essentially unaffected by the specific choice of donor moiety, whereas the HOMO levels (−4.6 to −5.6 eV) are more sensitive to the choice of donor. The DTT and DTP polymers with 3‐alkylthiophene bridge were found to exhibit hole mobilities of 8 × 10−5 and 3 × 10−2 cm2 V−1 s−1, respectively, in top‐contact organic field‐effect transistors. Power conversion efficiencies in the range 0.17–0.43% were obtained under simulated AM 1.5, 100 mW cm−2 irradiation for polymer solar cells using the DTT and DTP‐based polymers with 3‐alkylthiophene bridge as donor and fullerene derivatives as acceptor. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5498–5508, 2009
Selective 17‐β‐estradiol molecular imprinting
Authors: Farber Shimon , Green Bernard S. , Domb Abraham J. 
Published: September 2009

AbstractAn efficient novel method for the synthesis of a covalent molecularly imprinted polymer (MIP) highly specific to β‐estradiol have been developed. MIP prepared by both covalent and non covalent techniques, demonstrated high selectivity toward β‐estradiol. MIPs were synthesized by radical polymerization of 17‐β‐estradiol 4‐vinyl‐benzene carboxyl or sulfonyl esters used as covalent functional monomers, methacrylic acid as noncovalent functional monomer, ethylene glycol dimethacrylate as crosslinking agent, and acetonitrile as swelling and porogenic component. Almost 35% (w/w) of 17‐β‐estradiol was successfully removed from the polymer network by basic hydrolysis. The binding ability of MIP was 10.73 μg/mg MIP following removal of 17‐β‐estradiol in the 2 mg/mL β‐estradiol solution. Selective rebinding of β‐estradiol toward MIP was tested in the presence of competitive binders including estrone, 19‐nortestosterone, epiandrosterone, and cholesterol. Estrone having closest similar chemical structure to β‐estradiol exhibited only 0.6 μg/mg MIP competitive binding, being exposed to equivalent concentrations. Moreover, other competitive steroids demonstrated negligible affinity toward MIP indicating high selectivity of novel MIP system toward β‐estradiol. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5534–5542, 2009
New efficient reaction media for SET‐LRP produced from binary mixtures of organic solvents and H2O
Authors: Nguyen Nga H. , Rosen Brad M. , Jiang Xuan , Fleischmann Sven , Percec Virgil 
Published: September 2009

AbstractSET‐LRP is mediated by a combination of solvent and ligand that promotes disproportionation of Cu(I)X into Cu(0) and Cu(II)X2. Therefore, the diversity of solvents suitable for SET‐LRP is limited. SET‐LRP of MA in a library of solvents with different equilibrium constants for disproportionation of Cu(I)X such as DMSO, DMF, DMAC, EC, PC, EtOH, MeOH, methoxyethanol, NMP, acetone and in their binary mixtures with H2O was examined. H2O exhibits the highest equilibrium constant for disproportionation of Cu(I)X. The apparent rate constant of the polymerization exhibits a linear increase with the addition of H2O. This is consistent with higher equilibrium constants for disproportionation generated by addition of H2O to organic solvents. Furthermore, with the exception of alcohols and carbonates, the rate constant of polymerization in binary mixtures could be correlated with the Dimroth‐Reichardt solvent polarity parameter. This is consistent with the single‐electron transfer mechanism proposed for SET‐LRP that involves a polar transition state. These experiments demonstrate that the use of binary mixtures of solvents with H2O provides a new, simple and efficient method for the elaboration of a large diversity of reaction media that are suitable for SET‐LRP even when one of the two solvents does not mediate disproportionation of Cu(I)X. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5577–5590, 2009
Prediction of yield and long‐term failure of oriented polypropylene: Kinetics and anisotropy
Authors: van Erp Tim B. , Reynolds Chris T. , Peijs Ton , van Dommelen Johannes A. W. , Govaert Leon E. 
Published: September 2009

AbstractThe time‐dependent yield and failure behavior of off‐axis loaded uniaxially oriented polypropylene tape is investigated. The yield and failure behavior is described with an anisotropic viscoplastic model. A viscoplastic flow rule is used with an equivalent stress, based on Hill's anisotropic yield criterion, and the Eyring flow theory combined with a critical equivalent strain definition. This model is based on factorization of the rate and draw ratio dependence and is capable of quantitatively predicting the rate, angle and draw ratio dependence of the yield stress as well as time‐to‐failure in various off‐axis tensile loading conditions characterized solely from the transverse direction. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2026–2035, 2009
Enhancement in solubility and conductivity of polyaniline with lignosulfonate modified carbon nanotube
Authors: Dong Jin‐Qiao , Shen Qing 
Published: September 2009

AbstractAn organic solvent soluble and high electrical conductivity, for example, 55.43 S/cm, polyaniline (PANI), was synthesized by a novel method. In this two steps process, a noncovalent approach was initially developed by functionalization of multiwalled carbon nanotubes (MWNTs) using calcium lignosulfonate (LsCa) via self‐assembly to result MWNTs‐LsCa. Then, the MWNT‐LsCa was employed as a template to lead anilinium monomers directly aligned on the surface to start the polymerization of PANI. The noncovalent modification of MWNTs avoided their agglomeration effectively to allow them doped in PANI at the molecular level. The obtained novel PANI/MWNTs‐LsCa presented excellent solubility and high conductivity. The recorded scanning electron microscopy photographs revealed that the MWNTs‐LsCa was wrapped with PANI chains that caused the crystal orientation improvement. In this article, a related scheme on resulting in the high conductivity of PANI/MWNTs‐LsCa was showed and described. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2036–2046, 2009
Some Examples of Temperature and Time Resolved Studies of the Dehydration and Hydration Behavior of Zeolites and Clathrates
Authors: Depmeier Wulf 
Published: September 2009

AbstractThe prominent role of X‐ray powder diffraction (XRPD) for the study of the dehydration and hydration behavior of microporous zeolites and clathrates can be documented by several typical examples taken from the literature. The importance of various interactions, in particular water‐framework, water‐extra‐framework cations, framework‐extra‐framework cations, and water‐water is discussed. However, it is emphasized that XRPD has its limitations, especially when species are disordered, and should be complemented as far as possible by the determination of bulk properties, and also by various appropriate spectroscopic methods.
Fast XRD2 Microdiffraction with Focusing X‐Ray Microlenses
Authors: Berthold Christoph , Bjeoumikhov Aniouar , Brügemann Lutz 
Published: September 2009

AbstractThe advantages using specially designed X‐ray‐polycapillary microlenses with spot sizes of 50 μm to 200 μm in a commercially available BRUKER D8 DISCOVER GADDS XRD2‐microdiffractometer with a standard sealed X‐ray tube instead of a microfocus source are shown and compared to commercially available pin hole collimators or monocapillary optics.The application of a focusing X‐ray microlens instead of a monocapillary optic with similar spot size leads to an increase of the primary beam flux by a factor of approximately 10 to larger than 100 depending on the additional pinhole used at the exit of the microlens. This additional pinhole can be used to optimize the beam geometry for a better peak profile without additional changes on the setup. Therefore the use of a focusing X‐ray microlens instead of a mono capillary optic reduces the measurement time by at least a factor of 10. A factor up to 200 is possible by simple changing the diameter of the exit pinhole – for the price of a wider peak profile. Due to the similar housing the focusing X‐ray microlens fits in the standard collimator support enabling switching between collimators, mono‐capillaries and the microlens without realignment. This is why no time consuming modification of the microdiffractometer is needed.
X‐Ray Diffractometry with Low Power Microfocus Sources – New Possibilities in the Lab
Authors: Wiesmann Jörg , Graf Jürgen , Hoffmann Christian , Hembd Alexandra , Michaelsen Carsten , Yang Ning , Cordes Holger , He Bob , Preckwinkel Uwe , Erlacher Kurt 
Published: September 2009

AbstractResults from a new type of stationary microfocusing sealed tube X‐ray source will be presented here. Measurements obtained with the new low maintenance, high brilliance microfocus source IμS™ equipped with different 2‐dimensional beam shaping multilayer optics are shown. A comparison of the IμS source with typical sealed tube fine focus systems shows data of outstanding quality achieved in diffractometry applications using a 2‐dimensional detector. A large improvement in intensity (by a factor of about 16) was observed. Very promising results were achieved when measuring powders in transmission geometry using the IμS. With this way of focusing on the detector, better crystallite statistics and better resolution were provided. Intensity gain factors in the range of 100 were possible with some applications. For small angle scattering a factor of five was observed when using an IμS with optics for a parallel beam in comparison to a typical sealed tube instrument.
Therapeutic bronchoscopy in a child with sand aspiration and respiratory failure from near drowning—case report and literature review
Authors: Kapur N. , Slater A. , McEniery J. , Greer M.L. , Masters I.B. , Chang A.B. 
Published: September 2009

AbstractForeign matter aspiration occurs relatively commonly in drowning and near‐drowning events. In most cases, stomach contents are aspirated. Sand aspiration rarely occurs and there are no reported cases in children with near drowning. Limited data are available on clinical presentation and management of sand aspiration with accidental burial. We report a 3‐year‐old boy who nearly drowned while swimming in brackish waters and was found face down in sand. Sand aspiration was suspected when the child continued to have persistent wheezing and high ventilatory requirement despite intensive bronchodilator and corticosteroids therapy with an inability to wean after 4 days post‐near‐drowning event. Radiology was non‐specific in the absence of sand bronchogram. Presence of sand in the airways was confirmed when a bronchoscopy was undertaken and sand seen in the bronchoalveolar lavage fluid. Sequential lung washing followed by exogenous surfactant administration (3 ml/kg) was undertaken and lead to significant improvement such that within 12 hr post‐therapeutic lavage, his ventilatory requirements reduced substantially. The child was extubated 4 days post‐lavage and on review 2 months post‐event, was clinically well with airway resistance within normal predicted values measured on forced oscillatory spirometry (IOS). Pediatr Pulmonol. 2009; 44:1043–1047. ©2009 Wiley‐Liss, Inc.
Leukotriene receptor antagonist in the treatment of childhood allergic rhinitis—a randomized placebo‐controlled study
Authors: Li Albert M. , Abdullah Victor J. , Tsen Chui S. , Au Chun T. , Lam Hugh S. , So Hung K. , Chan Michael H.M. , Leung Alex W.K. , Chan Iris H.S. , Lam Christopher W.K. , Ng Pak C. 
Published: September 2009

AbstractObjectiveThis study was designed to assess the hypothesis that leukotriene receptor antagonists (LTRAs) would provide additional symptom relief in asthmatic children with persistent AR already taking regular antihistamine. The effects of 16‐week treatment of LTRA in addition to fexofenadine (FEX) on persistent AR in asthmatic children were examined.Study DesignConsecutive children with stable asthma and persistent AR were invited in this randomized, double‐blind, placebo‐controlled study. After a 2‐week run‐in period in which subjects were given FEX alone, they were randomly assigned to take LTRA or placebo in addition to FEX for 16 weeks, followed by 8 weeks of follow‐up phase with FEX taken alone. Symptom scoring, rhinoscopy, acoustic rhinometry, spirometry, nasal secretion extraction and blood taking for IL‐4 and IL‐13 analysis were performed after a 2‐week run‐in and at the end of treatment.ResultsForty‐four subjects with a median (IQR) age of 12.2 (10.1–14.1) years were recruited. At week 4 of treatment, the between‐group differences in the mean changes of daytime sneezing score (mean difference (95% CI) = −0.35 (−0.59, −0.12), P = 0.004), nighttime sneezing score (mean difference (95% CI) = −0.37 (−0.62, −0.11), P = 0.007) and daytime composite score (mean difference (95% CI) = −1.08 (−1.92, −0.25), P = 0.013) were significant. Acoustic rhinometry also demonstrated a nearly significant difference in nasal volume change between groups at 16 weeks of treatment (mean difference (95% CI) = 0.572 (0.090–1.054), P = 0.021). IL‐4 and IL‐13 were not detected in the majority of nasal secretion or serum samples.ConclusionsAdditional LTRA provided a more rapid relief on sneezing at the 4‐week time point. This combination therapy also maintained a greater nasal volume and this might translate to lesser nasal congestion. Pediatr Pulmonol. 2009; 44:1085–1092. ©2009 Wiley‐Liss, Inc.
Identity crisis: on the problem of namespace design for ID‐PKC and MANETs
Authors: Balfe Shane , McDonald Andrew D. , Paterson Kenneth G. , Phillips Helen 
Published: September 2009

AbstractIn this paper, we explore the ‘interface’ between identity‐based public key cryptography (ID‐PKC) and mobilead hocnetworks (MANETs). In particular, we examine the problem of naming and namespace design in an identity‐based key infrastructure (IKI). We examine the potential impact that different types of identifiers may have on the utility ofad hocnetworks where an IKI provides the underlying key infrastructure. We also highlight a number of open problems inherent in extending namespaces to allow inter‐operability amongst heterogeneous trust domains. Copyright © 2009 John Wiley & Sons, Ltd.
Nachweiskonzepte zur Bemessung ermüdungsbeanspruchter Bauteile unter Berücksichtigung von Schweißnahtnachbehandlungsverfahren durch höherfrequentes Hämmern
Authors: Günther Hans‐Peter , Kuhlmann Ulrike 
Published: September 2009

AbstractDie Anwendung von höherfrequenten Hämmerverfahren zur Erhöhung der Ermüdungsfestigkeit von dynamisch beanspruchten Bauteilen gewinnt zunehmend an Bedeutung. Dies hängt zum einen damit zusammen, dass bei Neukonstruktionen durch den Einsatz von höherfesten Stählen die Frage der Materialermüdung verstärkt die Bauteilauslegung bestimmt, und zum anderen, dass bei vielen bestehenden Bauwerken vermehrt Maßnahmen zur Verlängerung der Restlebensdauer erforderlich werden. Die Anwendung von Schweißnahtnachbehandlungsverfahren in Form von höherfrequentem Hämmern stellt hierfür eine geeignete Maßnahme dar, die Ermüdungsfestigkeit von Neukonstruktionen zu erhöhen bzw. die Restlebensdauer bestehender Anlagen zu verlängern. Eine zuverlässige baupraktische Anwendung setzt jedoch die Existenz anerkannter Regeln für die Bemessung voraus, wie auch eine darauf abgestimmte Vorgehensweise für die Ausführung. Der vorliegende Beitrag widmet sich vor allem der Darstellung bisher existierender Nachweiskonzepte für die Bemessung ermüdungsbeanspruchter Bauteile bei Anwendung von Schweißnahtnachbehandlungsverfahren in Form von höherfrequentem Hämmern.Fatigue design concepts for post‐weld treated joints improved by high frequency hammer peening methods.Post‐weld improvement methods have been widely investigated and have in most cases been found to give substantial increases in the fatigue strength. Nowadays, there is an increasing interest in using such methods in order to either improve the fatigue resistance of new structures built e.g. by high strength steel and/or to enlarge the lifetime of existing structures suffering from fatigue problems. With regard to this, post‐weld improvement using high frequency hammer peening methods lately showed very good and promising results in combination with simple operation conditions.However, the successful application of post‐weld improvement methods always requires the existence of profound fatigue design concepts as well as relevant execution and quality standards. The following paper refers predominately to the first aspect, in trying to summarise and compare existing design concepts and their application range for high frequency hammer peening methods.
HiFIT – Technische Entwicklung und Anwendung
Authors: Telljohann Gerd , Dannemeyer Sven 
Published: September 2009

AbstractDas Verbundprojekt REFRESH bot in den vergangenen drei Jahren eine ideale Plattform für die theoretische und experimentelle Weiterentwicklung des HiFIT (high frequency impact treatment)‐Verfahrens. So konnten sowohl die Behandlungsparameter an umfangreichen Schweißproben optimiert als auch ein industrietaugliches Gerätedesign unter Einbeziehung zahlreicher Anwendungsfälle aus der Praxis der Industriepartner entwickelt werden. Effizienz, Ergonomie und die Qualitätssicherung standen bei der Entwicklung im Vordergrund. Die Beurteilung der Anwendbarkeit des Verfahrens und die Anwendung selbst sollten im Sinne einer allgemeinen Qualitätssicherung und zur Quantifizierung des zu erwartenden Behandlungserfolgs von geschultem Personal durchgeführt werden. Letzteres gilt nicht nur im Speziellen für das HiFIT‐Verfahren, sondern generell für alle Nachbehandlungsverfahren. Hinter dem Markennamen HiFIT steht ein ganzheitliches Lösungskonzept mit rechnerischen Analysetools, Nachbehandlungswerkzeugen, Schulung und Consulting zur effizienten Steigerung der Betriebsfestigkeit neuer und bereits im Einsatz befindlicher Schweißkonstruktionen.HiFIT – Technical development and application.In the past three years the HiFIT technology for application on welded parts has been investigated in the REFRESH project. Many treatment parameters have been tested. Using prototype devices a lot of experience has been gained by treatment of several parts in cooperation with the project partners. The design of the HiFIT device is optimized for industrial application where efficiency, ergonomics and quality assurance are the main topics. An application benchmark of HiFIT and the treatment should be done only by specially trained employees. This restriction is not only HiFIT specific. The trademark HiFIT means a solution for improvement of fatigue strength of new and cyclic pre‐damaged welded structures. The solution contains assessment of fatigue strength, treatment devices, training and consulting.