bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of processing conditions on the rheological behavior of crumb tire rubber‐modified bitumen
Authors: Navarro F. J. , Partal P. , Martínez‐Boza F. J. , Gallegos C. 
Published: February 2007

AbstractTraditional or technological studies about crumb tire rubber‐modified bitumens (CTRMBs) do not provide detailed rheological information. In that way, this article describes the influence of processing conditions on the linear viscoelastic and viscous behaviors of CTRMBs. The results of the study reveal an exponential increase in dissolved/dispersed rubber with processing temperature and, therefore, lower solid content that affect the rheological behavior in different ways. No influence of the processing device was observed, probably due to the fact that processing temperature (180°C) was not high enough to break up the crosslinked network of the rubber. The presence of rubber particles avoids the negative hardening effects observed for unmodified bitumens, resulting in a more flexible binder at low temperature. At high in‐service temperature, better rutting resistance would also be expected for CTRMBs. Flow results at 135°C indicates that modified bitumens can satisfy the AASHTO MP1 requirements if high‐enough shear rates are reached. All the CTRMBs studied present segregation, due to rubber settling during storage at high temperature, although an increase in processing temperature seems to enhance its stability. The results obtained seem to indicate that the optimum CTRMB processing temperature is 210°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1683–1691, 2007
Photodegradation of ethylene/propylene/polar monomers, co‐, and terpolymers. II. Prepared by Ni catalyst systems
Authors: Fernandes Susete , Correia Sandra , Matos Inês , Marques Maria M. , Rana Sravendra , Kumar Bijandra , Gupta M. K. , Singh R. P. 
Published: February 2007

AbstractThe copolymers of ethylene/propylene as well as their terpolymers with polar monomers were prepared by Ni‐catalyst systems and their photodegradation behavior was studied by Fourier transform infrared spectroscopy. The polar monomers used to synthesize co‐ and terpolymers of ethylene/propylene/polar monomer were 5‐hexen‐1‐ol, 10‐undecen‐1‐ol, acrylamide, methylmethacrylate, acrylonitrile, and methylvinyl ketone. The morphological changes of the irradiated samples were determined by scanning electron microscopy. The photodegradation kinetics has also been studied. The surface damage caused by polychromatic irradiation (λ ≥ 290 nm) at 55 °C in atmospheric air is presented in different micrographs. The rate of photo‐oxidative degradation is very fast in terpolymers containing polar monomers as compared with copolymers and homopolymers. The morphological study of the photodegraded samples showed a very good correlation with the photodegraded results. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1783–1791, 2007
Synthesis of hydrosoluble polymers of oxazoline using Maghnite‐H as catalyst
Authors: Yahiaoui Ahmed , Hachemaoui Aïcha , Belbachir Mohammed 
Published: February 2007

Abstract2,4,4‐Triméthyl‐2‐oxazoline was polymerized, using an acid exchanged montmorillonite clay as catalyst, with the aim to study the influence of the methyl group size in the initiation and propagation processes. The effect of amount of catalyst temperature, time, and solvent on the polymerization yield and viscosity of the polymers were studied. The polymers obtained were characterized by spectrometric methods and their average molecular weights were determined by viscosimetrie and GPC data. The polymers presented similar spectrometric results and narrow molecular weight distributions. The kinetics indicated that the polymerization rate is first order with respect to monomer concentration. The polymerization results showed that the methyl groups present in the monomer affected the initiation process. Mechanism studies showed that polymerization of TMOX involves nucleophilic ring opening by attack of nitrogen to cleave the CH2O bond of the oxazoline ring. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1792–1800, 2007
Mechanical properties of PBT/ABAS blends
Authors: Tomar Neetu , Maiti S. N. 
Published: February 2007

AbstractThe mechanical properties such as tensile behavior and impact strength of melt mixed poly(butylene terephthlate) (PBT)/acrylonitrile–butylacrylate–styrene (ABAS) terpolymer blends at ABAS contents up to 39 vol % were evaluated. Tensile properties decreased while impact strength was enhanced by the blending polymer. Morphological studies show good dispersion of ABAS into the PBT matrix. The strength properties were dependent on the crystallinity of PBT and interphase adhesion between the phases. The impact toughening was dependent on the blending rubber concentration and interparticle distance of the discrete phase. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1807–1817, 2007
Morphology and thermomechanical properties of recycled PET–organoclay nanocomposites
Authors: Bizarria Maria T. M. , Giraldi André L. F. de M. , de Carvalho Cesar M. , Velasco Jose I. , d'Ávila Marcos A. , Mei Lucia H. I. 
Published: February 2007

AbstractRecycled PET/organoclay nanocomposites were prepared by melt intercalation process with several amounts (1, 3, and 5 wt %) of clay modified with quaternary ammonium salt (DELLITE 67G) dispersed in a recycled poly(ethylene terephthalate) (rPET) matrix. The resultant mechanical properties (modulus and yield strength) of the nanocomposites were found to be different from those of rPET. Wide angle X‐ray scattering (WAXS) and Transmission Electron Microscopy (TEM) measurements have shown that although complete exfoliation was not achieved, delaminated clay platelets could be observed. Thermal analysis did not show significant changes in the thermal properties from those of recycled PET. Mechanical testing showed that nanocomposite properties were superior to the recycled PET in terms of strength and elasticity modulus. This improvement was attributed to nanoscale effects and strong interaction between the rPET matrix and the clay interface, as revealed by WAXS and TEM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1839–1844, 2007
Rheology and transesterification between polycarbonate and polyesters
Authors: Nabar Sanket , Kale D. D. 
Published: February 2007

AbstractRheological behavior of polycarbonate (PC)–polyester blends is studied. The miscibility and rheological behavior are discussed. Effect of catalyst, tetra‐n‐butyl orthotitanate on the transesterification reactions for a [60 (PC):40 (PET or PBT)] blend is studied rheologically. The blends were mixed for different spans of time for rheological study. The blends are analyzed on the basis of the mechanism suggested by other researchers. As the mixing time is increased, the blends show decrease in viscosity. Random copolymers also are amorphous in nature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2039–2047, 2007
Effects of silane and the lowering of pH on the properties of phenol–formaldehyde resol resins and resin coatings
Authors: Monni Janne , Alvila Leila , Rainio Jouni , Pakkanen Tuula T. 
Published: February 2007

AbstractPhenol–formaldehyde resol resins were modified by the addition of silane (3‐aminopropyltriethoxysilane) and the lowering of pH (formic acid). The effects of the modifications on the properties of the resins during storage were studied through comparison with the parent resins and by viscosity measurements, NMR spectroscopy, ultraviolet–visible spectroscopy, and differential scanning calorimetry. Resin coatings on paper were prepared to determine the influence of discoloration of the resin solution on the color of the cured resin. A decrease in the pH of the NaOH‐catalyzed resin solutions lightened the color of the solutions and corresponding coatings, whereas silane additions made the coatings slightly more yellow. The lowering of pH increased the viscosities and decreased the reactivities of the resin solutions compared with the unmodified reference resins during storage. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1933–1941, 2007
Studies on miscibility of polyacrylamide/polyethylene glycol blends
Authors: Swamy T. M. Mruthyunjaya , Siddaramaiah  
Published: February 2007

AbstractMiscibility studies have been conducted on solutions of blends of polyacrylamide (PAAm) and polyethylene glycol (PEG) over an extended range of concentrations in water. The ultrasonic velocity, viscosity, density, and refractive index of the blends have been measured for different compositions viz., 0/100, 10/90, 20/80, 30/70, 40/60, 50/50, 60/40, 70/30, 80/30, 90/10, and 100/0 of PAAm/PEG blends at 30°C. The interaction parameters such as μ and α have been evaluated using the viscosity data to probe the miscibility. The obtained results have been confirmed by the ultrasonic velocity, density, and refractive index. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2048–2053, 2007
Preparation and properties of multiwalled carbon nanotube/polycaprolactone nanocomposites
Authors: Saeed Khalid , Park Soo‐Young 
Published: February 2007

AbstractMultiwalled carbon nanotube/polycaprolactone nanocomposites (MWNT/PCL) were prepared by in situ polymerization, whereby as‐received MWNTs (P‐MWNTs) and purified MWNTs (A‐MWNTs) were used as reinforcing materials. The A‐MWNTs were purified by nitric acid treatment, which introduced the carboxyl groups (COOH) on the MWNT. The micrographs of the fractured surfaces of the nanocomposites showed that the A‐MWNTs in A‐MWNT/PCL were better dispersed than P‐MWNTs in PCL matrix (P‐MWNT/PCL). Percolation thresholds of the P‐MWNT/PCL and A‐MWNT/PCL, which were studied by rheological properties, were found at ∼2 wt % of the MWNT. The conductivity of the P‐MWNT/PCL was between 10−1 and 10−2 S/cm by loading of 2 wt % of MWNT although that of the A‐MWNT/PCL reached ∼10−2 S/cm by loading of 7 wt % of MWNT. The conductivity of the P‐MWNT/PCL was higher than that of the A‐MWNT/PCL at the entire range of the studied MWNT loading, which might be due to the destruction of π‐network of the MWNT by acid treatment, although the A‐MWNT/PCL was better dispersed than the P‐MWNT/PCL. The amount of the MWNT at which the conductivity of the nanocomposite started to increase was strongly correlated with the percolation threshold. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1957–1963, 2007
Free‐radical copolymerization of 2‐[3‐(6‐tetralino)‐3‐methylcyclobutyl]‐2‐ketoethyl methacrylate with acrylonitrile and styrene: Synthesis, characterization, and monomer reactivity ratios
Authors: Erol Ibrahim , Ahmedzade Mısır 
Published: February 2007

AbstractThe copolymerization of the monomer 2‐[3‐(6‐tetralino)‐3‐methylcyclobutyl]‐2‐ketoethyl methacrylate with acrylonitrile and styrene was carried out in a 1,4‐dioxane solution at 60°C with 2,2′‐azobisisobutyronitrile as an initiator. The copolymers were characterized with Fourier transform infrared, 1H‐NMR, and 13C‐NMR spectroscopy techniques. The thermal properties of the polymers were also studied with thermogravimetric analysis and differential scanning calorimetry. The copolymer compositions were determined with elemental analysis and 1H‐NMR techniques. The monomer reactivity ratios were calculated by the application of conventional linearization methods (Fineman–Ross and Kelen–Tüdös) to be less than 1 for both monomers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1979–1986, 2007
Preparation of cardanol–formaldehyde resins from cashew nut shell liquid for the reinforcement of natural rubber
Authors: Chuayjuljit S. , Rattanametangkool P. , Potiyaraj P. 
Published: February 2007

AbstractNatural rubber was reinforced with a high loading of a cardanol–formaldehyde resin prepared from cashew nut shell liquid. Cardanol–formaldehyde resins, both resoles and novolaks, were synthesized from cardanol, which was extracted from cashew nut shells. This was done by the condensation polymerization of cardanol and formaldehyde in the presence of base and acid catalysts. The cardanol–formaldehyde resole with the highest yield (ca. 75%) was prepared with a formaldehyde/cardanol molar ratio of 2.0 at pH 8.0 and 90°C for 8 h. The cardanol–formaldehyde novolak with the highest yield (ca. 80%) was prepared with a formaldehyde/cardanol molar ratio of 0.8 at pH 2.2 and 100°C for 7 h. Fourier transform infrared and 13C‐NMR were employed to characterize the chemical structures of the obtained cardanol–formaldehyde resins. The resins were compatible with natural rubber in various formulations. The cured behaviors of natural rubber blended with the cardanol–formaldehyde resole and novolak resins were investigated. The cured behaviors of cardanol–formaldehyde resole and cardanol–formaldehyde novolak samples were different, reflecting differences in their chemical reactivities. Furthermore, the incorporation of cardanol–formaldehyde resins into natural rubber provided significant improvements in mechanical properties such as the hardness, tensile strength, modulus at 100 and 300% elongation, and abrasion resistance. However, the elongation at break and compression set of the blends decreased as expected. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1997–2002, 2007
Mixed method approaches to the investigation and mapping of buried Quaternary deposits: examples from southern England
Authors: Bates Martin R. , Bates C. Richard , Whittaker John E. 
Published: February 2007

AbstractThe lower reaches of major river valleys usually present archaeologists with considerable problems where thick sequences of stratified alluvium bury archaeology. These situations are typical of the lower reaches of major river systems that are currently under intense pressure from urban development where the archaeological resource is consequently at risk. Here we demonstrate how mixed method approaches, utilizing a range of borehole methods, cone penetration testing and surface and subsurface geophysics coupled with microfossil assessment (Foraminifera/Ostracoda), can be used to model these deposits and predict locations and depths at which important archaeological remains may be located. The novelty of this approach is not in the application of individual techniques to the problem but in the combined methodology, which enables a structured and cost effective programme of works to be formulated and provides the best chance to understand the subsurface. Although this approach has been developed to facilitate the location of archaeological sites buried at depth within the route corridor of development projects it is also suitable for locating fossil‐bearing sequences and mapping stratigraphical units in Quaternary science. We demonstrate the approach using two examples from southern England. Copyright © 2007 John Wiley & Sons, Ltd.
The expectation of aggregate discounted dividends for a Sparre Anderson risk process perturbed by diffusion
Authors: Meng Hui , Zhang Chunsheng , Wu Rong 
Published: February 2007

AbstractIn this paper, we study the expectation of aggregate dividends until ruin for a Sparre Andersen risk process perturbed by diffusion under a threshold strategy, in which claim waiting times have a common generalized Erlang(n) distribution. For this strategy, we assume that if the surplus is above certain threshold level before ruin, dividends are continuously paid at a constant rate that does not exceed the premium rate, and if not, no dividends are paid. We obtain some integro‐differential equations satisfied by the expected discounted dividends, and further its renewal equations. Finally, applying these results to the Erlang(2) risk model perturbed by diffusion, where claims have a common exponential distributions, we give some explicit expressions and numerical analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Do electrostatic interactions destabilize protein–nucleic acid binding?
Authors: Qin Sanbo , Zhou Huan‐Xiang 
Published: February 2007

AbstractThe negatively charged phosphates of nucleic acids are often paired with positively charged residues upon binding proteins. It was thus counter‐intuitive when previous Poisson–Boltzmann (PB) calculations gave positive energies from electrostatic interactions, meaning that they destabilize protein–nucleic acid binding. Our own PB calculations on protein–protein binding have shown that the sign and the magnitude of the electrostatic component are sensitive to the specification of the dielectric boundary in PB calculations. A popular choice for the boundary between the solute low dielectric and the solvent high dielectric is the molecular surface; an alternative is the van der Waals (vdW) surface. In line with results for protein–protein binding, in this article, we found that PB calculations with the molecular surface gave positive electrostatic interaction energies for two protein–RNA complexes, but the signs are reversed when the vdW surface was used. Therefore, whether destabilizing or stabilizing effects are predicted depends on the choice of the dielectric boundary. The two calculation protocols, however, yielded similar salt effects on the binding affinity. Effects of charge mutations differentiated the two calculation protocols; PB calculations with the vdW surface had smaller deviations overall from experimental data. © 2007 Wiley Periodicals, Inc. Biopolymers 86: 112–118, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Letter 1: Randomized clinical trial of the effect of postoperative intravenous fluid restriction on recovery after elective colorectal surgery (Br J Surg 2006; 93: 1469–1474)
Authors: Tornero-Campello G 
Published: February 2007

Abstract
The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Neural Networks as a Tool To Classify Compounds According to Aromaticity Criteria
Authors: Alonso Mercedes , Herradón Bernardo 
Published: February 2007

AbstractAromaticity is a fundamental concept in chemistry, with many theoretical and practical implications. Although most organic compounds can be categorized as aromatic, non‐aromatic, or antiaromatic, it is often difficult to classify borderline compounds as well as to quantify this property. Many aromaticity criteria have been proposed, although none of them gives an entirely satisfactory solution. The inability to fully arrange organic compounds according to a single criterion arises from the fact that aromaticity is a multidimensional phenomenon. Neural networks are computational techniques that allow one to treat a large amount of data, thereby reducing the dimensionality of the input set to a bidimensional output. We present the successful applications of Kohonen's self‐organizing maps to classify organic compounds according to aromaticity criteria, showing a good correlation between the aromaticity of a compound and its placement in a particular neuron. Although the input data for the training of the network were different aromaticity criteria (stabilization energy, diamagnetic susceptibility, NICS, NICS(1), and HOMA) for five‐membered heterocycles, the method can be extended to other organic compounds. Some useful features of this method are: 1) it is very fast, requiring less than one minute of computational time to place a new compound in the map; 2) the placement of the different compounds in the map is conveniently visualized; 3) the position of a compound in the map depends on its aromatic character, thus allowing us to establish a quantitative scale of aromaticity, based on Euclidean distances between neurons, 4) it has predictive power. Overall, the results reported herein constitute a significant contribution to the longstanding debate on the quantitative treatment of aromaticity.
Use of Anions To Allow Translational Isomerism of a [2]Rotaxane
Authors: Lin Chi‐Feng , Lai Chien‐Chen , Liu Yi‐Hung , Peng Shie‐Ming , Chiu Sheng‐Hsien 
Published: February 2007

AbstractWe report a molecular [2]rotaxane which comprises a molecular cage and a dumbbell‐shaped component, in which translational isomerism can be performed reversibly through an in situ anion exchange process, that is, sequential addition of Bu4NCl/AgPF6 reagent pairs. The [2]rotaxane incorporates two pyridinium and two dialkylammonium centers and functions as a triply operable molecular switch, which can be controlled through altering the polarity of the solvent, adding acidic and basic reagents (TFA/Et3N), and the varying the nature of the counteranions (Cl− vs PF6−).
Stereoelectronic Effects in Cyclic Sulfoxides, Sulfones, and Sulfilimines: Application of the Perlin Effect to Conformational Analysis
Authors: Wedel Tobias , Müller Monika , Podlech Joachim , Goesmann Helmut , Feldmann Claus 
Published: February 2007

AbstractThe 1JCH coupling constants in conformationally constrained sulfoxides, bissulfoxides, sulfoxide‐sulfones, and sulfilimines derived from 2‐benzylidene‐1,3‐dithiane and 2‐(2,2‐dimethylpropylidene)‐1,3‐dithiolane were measured by means of HMQC and HSQC NMR experiments and the Perlin effects were calculated. The type and the relative configuration of SX groups (X= O, NTos) in these compounds have a strong influence on the magnitude of coupling constants for axial and equatorial CH bonds, respectively. Axial SO bonds give rise to a stereoelectronic effect on antiperiplanar axial CH bonds. The resultant weakening of the respective CH bonds leads to a smaller coupling constant than for a respective equatorial CH bond. Equatorial SO groups have an influence on β‐CH bonds through a homoanomeric effect. Here, the axial CH bond is weakened and a smaller coupling constant is measured. Sulfilimine groups show similar effects to sulfoxide groups.
Substrate‐Controlled and Site‐Selective [3+2] Cycloadditions of N‐Heterocyclic Carbene Derived Ambident Dipoles
Authors: Cheng Ying , Liu Mei‐Fang , Fang De‐Cai , Lei Xue‐Mei 
Published: February 2007

Abstract2‐Aryl thiocarbamoyl benzimidazolium and imidazolinium inner salts derived from benzimidazole and imidazoline carbenes are unique ambident C‐C‐S and C‐C‐N 1,3‐dipolar systems, which undergo highly efficient and site‐selective cycloaddition reactions with dimethyl acetylenedicarboxylate or dibenzoylacetylene to furnish spiro(imidazole‐2,3′‐thiophene) derivatives in excellent yields. When treated with ethyl propiolate, methyl acrylate or acrylonitrile, spiro(imidazole‐2,3′‐pyrrole) derivatives were formed in good yields. Theoretical studies revealed an asynchronous concerted mechanism for both the C‐C‐S and C‐C‐N 1,3‐dipolar cycloaddition reactions. The site selectivity in the [3+2] cycloaddition reaction of ambident 1,3‐dipoles was predictably regulated by both the electronic and steric effects of dipolarophiles.