bluuebunny/crossref_metadata_2025_split huggingface dataset:
Irreversible phase behavior of the ternary blends of poly(ethylene terephthalate)/poly(ethylene‐2,6‐naphthalate)/poly(ethylene terephthalate‐ co‐ethylene‐2,6‐naphthalate)
Authors: Ida Shin‐Ichiro , Ito Masayoshi 
Published: July 2008

AbstractThe phase behavior of Poly(ethylene terephthalate)/Poly(ethylene‐2,6‐naphthalate)/Poly(ethylene terephthalate‐co‐ethylene‐2,6‐naphthalate) (PET/PEN/P(ET‐co‐EN)) ternary blends in molten state was evaluated from differential scanning calorimetry (DSC) and NMR results as well as optical microscopic observations. Copolymer of ethylene terephthalate and ethylene‐2,6‐naphthalate was prepared by a condensation polymerization, which was a random copolymer with an intrinsic viscosity (IV) of 0.3 dL/g. The phase diagram of the ternary blends revealed that the miscibility of ternary blends in molten state was dependent on the fraction of P(ET‐co‐EN) in the blends and holding time of the blends at high temperatures above 280°C. With increase in the holding time, the fraction of copolymer in the blends necessary to induce the immiscible to miscible transition decreased. For the blends with longer holding time at 280°C, the phase diagram in molten state was irreversible against the temperature, although a reversibility was found for the blends with short holding time of 1 min at 280°C. The irreversibility of phase behavior was not explained simply by the increase of copolymer content produced during heat treatment. Complex irreversible physical and chemical interactions between components and change of phase structure of the blend in the molten state might influence on the irreversibility. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Abrasion resistance of thermoplastic polyurethane materials blended with ethylene–propylene–diene monomer rubber
Authors: Tan Jing , Mei Ding Yu , Tao He Xu , Liu Yong , An Ying , Min Yang Wei 
Published: July 2008

AbstractThe effect of ethylene–propylene–diene monomer rubber (EPDM) as an additive on the abrasion resistance of a thermoplastic polyurethane (TPU) resin was investigated. The mechanical properties and microstructure of the resultant TPU/EPDM composites were evaluated, and the surface morphology of the composites after abrasion testing was examined. The results showed that the addition of EPDM greatly improved both the mechanical properties and abrasion resistance of the TPU resin. A TPU/EPDM composite with 8 wt % EPDM demonstrated the highest tensile strength, the largest elongation at break, and the best overall performance. The abrasion of this composite was 27 mg, whereas that of the pure resin was 73 mg. With the further addition of EPDM, the abrasion resistance of the resultant composites decreased, whereas the viscosity increased. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Poly(ethylene oxide) × polyacrylamide. Which one is more efficient to promote drag reduction in aqueous solution and less degradable?
Authors: Bizotto Vanessa C. , Sabadini Edvaldo 
Published: July 2008

AbstractThe hydrodynamic drag reduction (HDR) in aqueous solutions containing very small amounts of poly(ethylene oxide) (PEO) and polyacrylamide (PAM, 0–100 ppm) was studied under turbulent flow. In this condition, the polymers undergo severe mechanical degradation and loose their capacity to promote drag reduction. The interpretations from a molecular point of view of the mechanical degradation of these flexible polymers under turbulent flow are not consensual. To avoid effects of polymer entanglement and to correlate the mechanical degradation with the intrinsic characteristics of the polymer chain, a polymer concentration lower than 2 ppm was used. For this purpose, a highly accurate rheometer containing a double‐gap cell was used to determine the mechanical degradation kinetics. The kinetics was measured directly from the loss of the polymer's capability to promote drag reduction. The comparisons of degradation kinetics for PEO and PAM in aqueous solution allow us to conclude that the stabilities of the two polymers are similar. This new interpretation can be useful to understand the relative mechanical stability of flexible polymers under drag reduction conditions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
1H NMR, thermal, and conductivity studies on PVAc based gel polymer electrolytes
Authors: Baskaran R. , Selvasekarapandian S. , Kuwata N. , Iwai Yoshiki , Kawamura J. , Hattori T. 
Published: August 2008

AbstractThe lithium‐ion conducting gel polymer electrolytes (GPE), PVAc‐DMF‐LiClO4 of various compositions have been prepared by solution casting technique. 1H NMR results reveal the existence of DMF in the gel polymer electrolytes at ambient temperature. Structure and surface morphology characterization have been studied by X‐ray diffraction analysis (XRD) and scanning electron microscopy (SEM) measurements. Thermal and conductivity behavior of polymer‐ and plasticizer‐salt complexes have been studied by differential scanning calorimetry (DSC), TG/DTA, and impedance spectroscopy results. XRD and SEM analyses indicate the amorphous nature of the gel polymer‐salt complex. DSC measurements show a decrease in Tg with the increase in DMF concentrations. The thermal stability of the PVAc : DMF : LiClO4 gel polymer electrolytes has been found to be in the range of (30–60°C). The dc conductivity of gel polymer electrolytes, obtained from impedance spectra, has been found to vary between 7.6 × 10−7 and 4.1 × 10−4 S cm−1 at 303 K depending on the concentration of DMF (10–20 wt %) in the polymer electrolytes. The temperature dependence of conductivity of the polymer electrolyte complexes appears to obey the VTF behavior. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Using LiDAR to detect cultural resources in a forested environment: an example from Isle Royale National Park, Michigan, USA
Authors: Gallagher Julie M. , Josephs Richard L. 
Published: July 2008

AbstractThis article discusses the use of light detecting and ranging (LiDAR) technology as an effective remote sensing tool for the location of cultural resources. Its use, particularly in Europe, has proven successful in the identification of archaeological sites obscured by dense vegetation or surface disturbances. This study used LiDAR‐derived imagery to detect pre‐ and post‐European contact sites, and their related features, in densely forested environments on Isle Royale, Michigan, USA. LiDAR bare‐Earth models were used to ‘see through’ the vegetation in an effort to: (i) identify cultural features prior to the implementation of a pedestrian reconnaissance survey; (ii) aid in the development of a more informed survey strategy; and (iii) produce an overall safer, more efficient and more cost‐effective research design. Three study areas were selected for investigation. Within these three study areas, a total of seven investigation locales containing 32 separate features were identified using LiDAR‐derived imagery. Eighteen of the 32 features were found to have been previously recorded. Of the remaining 14 features, seven were confirmed in the field as being cultural features and were recorded for the first time as a result of this investigation. The remaining seven could not be located on the ground or were found to be non‐cultural. The results of this study support the use of LiDAR as a viable method for the detection of cultural resources, particularly in remote and heavily forested environments. Despite its positive contributions, there is a limited range of archaeological (surface) features that can be detected using this technology. As applied to archaeology, LiDAR is not an exclusive investigatory technique. It must be part of a comprehensive research strategy that integrates field, laboratory and archival investigation in order to achieve the best possible interpretation of the archaeological record. Copyright © 2008 John Wiley & Sons, Ltd.
Decreased Turn‐On Times of Single‐Component Light‐Emitting Electrochemical Cells by Tethering an Ionic Iridium Complex with Imidazolium Moieties
Authors: Su Hai‐Ching , Chen Hsiao‐Fan , Wu Chung‐Chih , Wong Ken‐Tsung 
Published: July 2008

AbstractWe report a significant decrease in turn‐on times of light‐emitting electrochemical cells (LECs) by tethering imidazolium moieties onto a cationic Ir complex. The introduction of two imidazolium groups at the ends of the two alkyl side chains of [Ir(ppy)2(dC6‐daf)]+(PF6)− (ppy=2‐phenylpyridine, dC6‐daf=9,9′‐dihexyl‐4,5‐diazafluorene) gave the complex [Ir(ppy)2(dC6MIM‐daf)]3+[(PF6)−]3 (dC6MIM‐daf=9,9‐bis[6‐(3‐methylimidazolium)hexyl]‐1‐yl‐4,5‐diazafluorene). Both complexes exhibited similar photoluminescent/electrochemical properties and comparable electroluminescent efficiencies. The turn‐on times of the LECs based on the latter complex, however, were much lower than those of devices based on the former. The improvement is ascribed to increased concentrations of mobile counterions ((PF6)−) in the neat films and a consequent increase in neat‐film ionic conductivity. These results demonstrate that the technique is useful for molecular modifications of ionic transition‐metal complexes (ITMCs) to improve the turn‐on times of LECs and to realize single‐component ITMC LECs compatible with simple driving schemes.
Asymmetric Transfer Hydrogenation of CO and CN Bonds by Tethered RhIII Catalysts
Authors: Matharu Daljit S. , Martins José E. D. , Wills Martin 
Published: July 2008

AbstractRhIII catalysts containing a tetramethylcyclopentadienyl group linked by a ‘tether’ to a tosylated diamine ligand have previously been reported by our group for the asymmetric transfer hydrogenation (ATH) of ketones. The extension of these catalysts to the asymmetric reduction of imines, as well as to more highly functionalized substrates is reported. In some cases, the catalysts give better ee values than other methods for these transformations at lower catalyst loadings. The introduction of a methoxy group into the tethering aryl ring does not negate the performance of the catalyst, thus opening up a route to supported derivatives.
Albert Einstein: Revolutionär oder “Bewahrer des Alten”?
Authors: Jung Tobias 
Published: July 2008

AbstractAlbert Einstein: Revolutionary or “Preserver of the Old”? Usually, Albert Einstein and his contributions to the special and general theory of relativity, to cosmology and to quantum physics are considered as “revolutionary”. However, Einstein himself named only one of the papers published in his annus mirabilis 1905 as “very revolutionary”, namely the paper about the light quantum hypothesis. He neither considered his papers about atomic theory nor the papers about the “Electrodynamics of Moving Bodies” as “revolutionary”. In the special and general theory of relativity Einstein did not see the redemption of Newtonian physics but rather its completion. In cosmology which was started off by Einstein's “Cosmological Considerations” in 1917 he adhered to the assumptions of a static and spherically closed universe which originally were introduced by him. His influence on the quantum theory can hardly be overestimated as he was the first to take Planck's light quantum hypothesis as serious physics. Moreover he introduced the concepts of probability and chance into quantum theory. Nonetheless he remained sceptical about quantum physics since he considered it as an incomplete and preliminary description of physical reality. Taking this into consideration one has to state that Einstein saw himself rather as a “preserver of classical physics” than as a revolutionary.
A Macrophage Cell Model for Selective Metalloproteinase Inhibitor Design
Authors: Jacobsen Faith E. , Buczynski Matthew W. , Dennis Edward A. , Cohen Seth M. 
Published: July 2008

AbstractThe desire to inhibit zinc‐dependent matrix metalloproteinases (MMPs) has, over the course of the last 30 years, led to the development of a plethora of MMP inhibitors that bind directly to the active‐site metal. With one exception, all of these drugs have failed in clinical trials, due to many factors, including an apparent lack of specificity for MMPs. To address the question of whether these inhibitors are selective for MMPs in a biological setting, a cell‐based screening method is presented to compare the relative activities of zinc, heme iron, and non‐heme iron enzymes in the presence of these compounds using the RAW264.7 macrophage cell line. We screened nine different zinc‐binding groups (ZBGs), four established MMP inhibitors (MMPis), and two novel MMP inhibitors developed in our laboratory to determine their selectivities against five different metalloenzymes. Using this model, we identified two nitrogen donor compounds—2,2′‐dipyridylamine (DPA) and triazacyclononane (TACN)—as the most selective ZBGs for zinc metalloenzyme inhibitor development. We also demonstrated that the model could predict known nonspecific interactions of some of the most commonly used MMPis, and could also give cross‐reactivity information for newly developed MMPis. This work demonstrates the utility of cell‐based assays in both the design and the screening of novel metalloenzyme inhibitors.
Modeling of Flow Burst, Flow Timing in Lab‐on‐a‐CD Systems and Its Application in Digital Chemical Analysis
Authors: Liu M. , Zhang J. , Liu Y. , Lau W. M. , Yang J. 
Published: July 2008

AbstractA theoretical model is developed to predict the time‐dependent behaviors of “flow burst” and centrifugal capillary flow in Lab‐on‐a‐CD systems. Enabling the calculation of flow field, flow burst, and flow timing as a function of fluid properties and system specifications, the model is a useful design tool for understanding and controlling flow behaviors in Lab‐on‐a‐CD devices. More importantly, the model shows great promise in the development of a new method for digital chemical analysis.
Classification of GC‐MS measurements of wines by combining data dimension reduction and variable selection techniques
Authors: Ballabio Davide , Skov Thomas , Leardi Riccardo , Bro Rasmus 
Published: July 2008

AbstractDifferent classification methods (Partial Least Squares Discriminant Analysis, Extended Canonical Variates Analysis and Linear Discriminant Analysis), in combination with variable selection approaches (Forward Selection and Genetic Algorithms), were compared, evaluating their capabilities in the geographical discrimination of wine samples. Sixty‐two samples were analysed by means of dynamic headspace gas chromatography mass spectrometry (HS‐GC‐MS) and the entire chromatographic profile was considered to build the dataset. Since variable selection techniques pose a risk of overfitting when a large number of variables is used, a method for coupling data dimension reduction and variable selection was proposed. This approach compresses windows of the original data by retaining only significant components of local Principal Component Analysis models. The subsequent variable selection is then performed on these locally derived score variables. The results confirmed that the classification models achieved on the reduced data were better than those obtained on the entire chromatographic profile, with the exception of Extended Canonical Variates Analysis, which gave acceptable models in both cases. Copyright © 2008 John Wiley & Sons, Ltd.
Skew‐normal linear calibration: a Bayesian perspective
Authors: Figueiredo Cléber da Costa , Sandoval Mônica Carneiro , Bolfarine Heleno , Lima Claudia Regina O.P. 
Published: July 2008

AbstractIn this paper, we present a Bayesian approach for estimation in the skew‐normal calibration model, as well as the conditional posterior distributions which are useful for implementing the Gibbs sampler. Data transformation is thus avoided by using the methodology proposed. Model fitting is implemented by proposing the asymmetric deviance information criterion, ADIC, a modification of the ordinary DIC. We also report an application of the model studied by using a real data set, related to the relationship between the resistance and the elasticity of a sample of concrete beams. Copyright © 2008 John Wiley & Sons, Ltd.
A Closer Look: Magnetic Behavior of a Three‐Dimensional Cyanometalate Coordination Polymer Dominated by a Trace Amount of Nanoparticle Impurity
Authors: Lefebvre Julie , Trudel Simon , Hill Ross H. , Leznoff Daniel B. 
Published: July 2008

AbstractThe structure and properties of the K{Ni[Au(CN)2]3} coordination polymer, prepared as a powder at room temperature and recrystallized hydrothermally, are reported. The structure of K{Ni[Au(CN)2]3} contains triply‐interpenetrated Prussian Blue type pseudo‐cubic arrays assembled from the alternation of octahedral NiII centers and [Au(CN)2]− bridging units. SQUID magnetometry studies have shown that K{Ni[Au(CN)2]3} displays typical paramagnetic behavior for isolated NiII centers down to 1.8 K. However, the magnetic behavior of the samples prepared under hydrothermal conditions suggests a superparamagnetic signature superimposed onto a paramagnetic background. After investigating the samples by transmission electron microscopy, it was determined that, in addition to K{Ni[Au(CN)2]3}, the high‐temperature (125, 135, and 165 °C) aqueous reaction of Ni(NO3)2⋅6 H2O with KAu(CN)2 also led to the formation of nanoparticles of NiO and Au as minor side products, and that these dominated the magnetic behavior. Nanoparticles of various sizes and shapes were observed, depending on the reaction conditions. Samples containing nanoparticles were found to be superparamagnetic, exhibiting blocking temperatures of ≈17–22 K, consistent with the behavior expected for NiO nanoparticles. These results illustrate the extreme care that must be taken when examining the physical properties of apparently analytically pure materials prepared by hydrothermal methods.
Reactivity and Antiproliferative Activity of Ferrocenyl–Tamoxifen Adducts with Cyclodextrins against Hormone‐Independent Breast‐Cancer Cell Lines
Authors: Buriez Olivier , Heldt Jan Martin , Labbé Eric , Vessières Anne , Jaouen Gerard , Amatore Christian 
Published: July 2008

AbstractHydroxyferrocifen compounds are a new and promising class of ferrocifen‐type breast‐cancer drug candidates. They possess both endocrine‐modulating properties and cytotoxic activity, which come from the tamoxifen skeleton and the presence of a ferrocene moiety, respectively. However, they suffer from reduced solubility in water, which presents a problem for their eventual therapeutic use. Herein, we examined the interactions of hydroxyferrocifen compounds with cyclodextrins (CDs) to evaluate whether or not their electron‐transfer oxidation pathways were affected by their inclusion. It has been demonstrated that these inclusion complexes are soluble in pure water, which shows that CDs can be used to deliver these biologically active molecules. Therefore, a series of these compounds has been investigated by cyclic voltametry in various media in the presence of CDs (β‐CD and Me‐β‐CD). In methanol, the hydroxyferrocifen compounds exhibited a weak interaction with the CD cavity. These interactions became stronger as the amount of added water increased. The complexation effect between the hydroxyferrocifen compounds and β‐CD was found to be stronger if the CD was partially methylated, which is probably due to hydrophobic effects between the cyclopentadienyl ring and/or the aromatic rings and the methoxy groups. Moreover, it appears that the structure of the hydroxyferrocifen compounds affects both their solubility and their complexation dynamics. Investigations in the presence of pyridine show that the base kinetically favors the dissociation of the ferrocifen–CD complex during the electron transfer step, but does not affect the follow‐up reactivity of the electrogenerated ferrocenium cation, which leads eventually to the corresponding quinone methide, as reported in the absence of CD. Accordingly, the cytotoxicity of these β‐CD‐encapsulated organometallic complexes in hormone‐independent breast‐cancer cells (MDA‐MB231) were confirmed to be similar to those obtained in the absence of cyclodextrin.
Optical Properties of Hybrid Dendritic–Mesoporous Titania Nanocomposite Films
Authors: Martínez‐Ferrero Eugenia , Franc Grégory , Mazères Serge , Turrin Cédric‐Olivier , Boissière Cédric , Caminade Anne‐Marie , Majoral Jean‐Pierre , Sanchez Clément 
Published: July 2008

AbstractNew hybrid optical sensors have been prepared by grafting specifically designed fluorescent, functionalised, phosphorus‐containing dendrimers onto a nanocrystalline mesoporous titania thin film formed by evaporation‐induced self‐assembly. The structural characterisation and optical behaviour of these new fluorescent probes have been studied both in solution and after being grafted onto an inorganic network, which resulted in the discovery of improved probing selectivity in the solid state. This new hybrid sensor exhibits high sensitivity to phenolic OH moieties (especially those from resorcinol and 2‐nitroresorcinol), which induce the quenching of fluorescence more efficiently in the solid state than in solution. This effect is a result of the increased spatial proximity of the fluorescent molecules, which is induced by pore confinement that makes the formation of hydrogen bonds between the hydroxyl moieties of the quenchers and the carbonyl groups of the dendrimer easier.
A Mesoporous 3D Hybrid Material with Dual Functionality for Hg2+ Detection and Adsorption
Authors: Ros‐Lis José V. , Casasús Rosa , Comes María , Coll Carmen , Marcos M. Dolores , Martínez‐Máñez Ramón , Sancenón Félix , Soto Juan , Amorós Pedro , Haskouri Jamal El , Garró Nuria , Rurack Knut 
Published: July 2008

AbstractDual‐function hybrid material U 1 was designed for simultaneous chromofluorogenic detection and removal of Hg2+ in an aqueous environment. Mesoporous material UVM‐7 (MCM41 type) with homogeneously distributed pores of about 2–3 nm in size, a large specific surface area exceeding 1000 m2 g−1, and nanoscale particles was used as an inorganic support. The mesoporous solid is decorated with thiol groups that were treated with squaraine dye III to give a 2,4‐bis(4‐dialkylaminophenyl)‐3‐hydroxy‐4‐alkylsulfanylcyclobut‐2‐enone (APC) derivative that is covalently anchored to the inorganic silica matrix. The solid was characterised by various techniques including X‐ray diffraction, transmission electron microscopy, Raman spectroscopy, and nitrogen adsorption. This hybrid solid is the chemodosimeter for Hg2+ detection. Hg2+ reacts with the APC fragment in U 1 with release of the squaraine dye into the solution, which turns deep blue and fluoresces strongly. Naked‐eye Hg2+ detection is thus accomplished in an easy‐to‐use procedure. In contrast, U 1 remains silent in the presence of other thiophilic transition metal ions, alkali and alkaline earth metal ions, or anions ubiquitously present in water such as chloride, carbonate, sulfate, and phosphate. Material U 1 acts not only as chemodosimeter that signals the presence of Hg2+ down to parts‐per‐billion concentrations, but at the same time is also an excellent adsorbent for the removal of mercury cations from aqueous solutions. The amount of adsorbed mercury ranges from 0.7 to 1.7 mmol g−1, depending on the degree of functionalisation. In addition, hybrid material U 1 can be regenerated for both sensing and removal purposes. As far as we know, U 1 is the first example of a promising new class of polyfunctional hybrid supports that can be used as both remediation and alarm systems by selective signalling and removal of target species of environmental importance. Model compounds based on silica gel (G 1), fumed silica (F 1), and micrometre‐sized MCM‐41 scaffolds (M 1) were also prepared and studied for comparative purposes.