bluuebunny/crossref_metadata_2025_split huggingface dataset:
Manipulation of the Microstructure of Injection Moldings in a Special Mold and Their Mechanical Behavior
Authors: Silva Cristina A. , Viana Júlio C. , Cunha António M. 
Published: November 2006

AbstractSummary: In this work, the relationships between the microstructure and the mechanical properties of injection moldings using a special mold for manipulation of their microstructure are studied. Distinct molding microstructures were obtained by superimposing a mold surface rotation action in different rotation modes during the filling stage of a center‐gated disk. For this, disks were injected in the special molding tool—the RCE mold—with distinct filling sequences (stationary, continuous, stepped, and pulsed rotation modes) for two different thicknesses (1.5 and 2.5 mm) in a propylene homopolymer. This enables the development of a wide range of microstructures, which were characterized by polarized light microscopy. The mechanical behavior of the moldings was assessed by tensile and impact testing. The results are presented in terms of the relationships between the developed microstructure and the assessed mechanical properties. The imposition of a rotation action of the molds wall influences the development of the microstructure, and hence the mechanical properties of the moldings.Effect of the rotating mode: stationary, continuous (R), stepped (RS), and pulsed modes (RC), at 150 rpm on the microstructure at position P2 (cuts to transversal flow direction). Thickness: 1.50 mm.magnified imageEffect of the rotating mode: stationary, continuous (R), stepped (RS), and pulsed modes (RC), at 150 rpm on the microstructure at position P2 (cuts to transversal flow direction). Thickness: 1.50 mm.
Miscibility in Blends of Isotactic/Syndiotactic Polystyrenes at Melt or Quenched Amorphous Solid State
Authors: Li Shu Hsien , Woo Eamor M. 
Published: November 2006

AbstractSummary: Miscibility in amorphous phase and behavior in a crystalline phase of blends of two semicrystalline and isomeric polymers, isotactic polystyrene (iPS) and syndiotactic polystyrene (sPS), was probed. Optical and scanning electron microscopy results indicate no discernible heterogeneity in iPS/sPS blends in either melt state or rapidly quenched amorphous super‐cooled state, while the Tg behavior of the quenched amorphous blends shows an intimately mixed state of two polymer chains. The crystal forms of the blends were further analyzed to provide additional evidence of miscibility in the amorphous domain. The sPS in the iPS/sPS blends upon melt crystallization was found to predominantly exist as the more stable β‐form (rather than mixed β‐form and α‐form in neat sPS), which also suggests evidence of miscibility in the iPS/sPS blends. The melting behavior of semicrystalline sPS in the iPS/sPS mixtures was analyzed using the Flory‐Huggins approach for estimation of interactions. By measuring the equilibrium melting point of the higher‐melting sPS species in the sPS/iPS blends, a small negative value, for the interaction parameter (χ ≈ −0.11) was found. Further, by introducing a third polymer, poly(2,6‐dimethyl‐p‐phenylene oxide) (PPO), a ternary iPS/sPS/PPO blend system was also proven miscible, which constituted a further test for stable phase miscibility in the iPS/sPS blend. General nature of miscibility in blends composed of two crystalline isomeric polymers is discussed. Issues in dealing with blends of polymers of the same chemical repeat unit but different tacticities were addressed.X‐ray diffractograms for neat sPS and iPS/sPS blends, each having been isothermally crystallized at 245 °C for 4 h.magnified imageX‐ray diffractograms for neat sPS and iPS/sPS blends, each having been isothermally crystallized at 245 °C for 4 h.
Chemical Recycling of PET by Glycolysis: Polymerization and Characterization of the Dimethacrylated Glycolysate
Authors: Karayannidis George P. , Nikolaidis Alexandros K. , Sideridou Irini D. , Bikiaris Dimitris N. , Achilias Dimitris S. 
Published: November 2006

AbstractSummary: In the framework of chemical recycling of polymers, leading to the generation of secondary value‐added products, PET flakes taken from post‐consumer soft drink bottles, were glycolyzed with DEG. The oligomers obtained were analyzed for their molecular weight and characterized by FT‐IR and POM. Subsequently, dimethacrylated oligoesters of PET glycolysate (PET‐GLY‐DMA) were synthesized by methacrylation of the glycolyzed PET product. The resulted monomer PET‐GLY‐DMA was studied by FT‐IR, POM and DSC. Thermal polymerization of this monomer was carried out at 80 °C in the presence of benzoyl peroxide as initiator. A UV‐curable formulation was also prepared on the basis of neat PET‐GLY‐DMA, as well as by mixing PET‐GLY‐DMA with styrene, using DMPA as photoinitiator. Nanoparticles of SiO2 were dispersed into PET‐GLY‐DMA/styrene copolymers as reinforcing agents and the mechanical properties of resins formed were studied.Preparation of methacrylated PET glycolysate.magnified imagePreparation of methacrylated PET glycolysate.
Influence of Carbon‐Black Nanoparticles on Poly(butylene terephthalate) Fractionated Crystallization in Bicomponent Poly(butylene terephthalate)/Poly[ethylene‐co‐(ethyl acrylate)] Blends
Authors: Pillin Isabelle , Feller Jean‐François 
Published: November 2006

AbstractSummary: The crystallization of the PBT minor phase in an EEA continuous matrix has been studied by DSC and SEM. When PBT is the minor phase, PBT crystallizes at a lower temperature, as expected, near Tc,f1 = 105 °C. Introducing different CB nanoparticles into the EEA continuous phase at contents increasing from 0.02 to 5 wt.‐% leads to important modifications of the PBT crystallization. A new PBT exotherm appears at Tc,f2 = 144 °C on the addition of CB, becoming really visible at Tc,f3 = 158 °C and finally moving to Tc,n = 185 °C at high content. The areas corresponding to these new peaks were found to increase to the detriment of that of the fractionated crystallization at Tc,f1 = 105 °C. Morphological studies and interfacial tension measurements were made to understand the surprising activity of the CB. Moreover, the substitution of the EEA phase with the less polar LLDPE confirmed the importance of the strong interactions developed by EEA with CB aggregates.Melting and recrystallization DSC curves for the PBT/EEA 60/40 blend.magnified imageMelting and recrystallization DSC curves for the PBT/EEA 60/40 blend.
A New Technique for Preparing a Filled Type of Polymeric Gradient Material
Authors: Zhu Yong‐Bin , Ning Nan‐ying , Sun Yang , Zhang Qin , Fu Qiang 
Published: November 2006

AbstractSummary: So‐called functionally gradient materials have received increased attention as a new type of composite whose microelements, including composition and structure, change spatially to optimize the gradient properties for a specific application. In this study, a new technique for continuously preparing a filled type of PGM was investigated through co‐extrusion/gradient distribution/2‐dimensional mixing with conventional polymeric material processing facilities. The processing line from co‐extrusion, gradient distribution to 2‐dimensional mixing was fulfilled by two extruders, a gradient distribution unit and 2‐dimensional mixing units. The gradient distribution unit and 2‐dimensional mixing units were designed separately in our group. As an example, a PE/GB PGM was prepared by using this new technique. The gradient variation of composition along the sample thickness direction was studied by TG and SEM. The TG results indicated that a gradient variation of the content of GB was formed along the thickness of the sample. The direct gradient distribution of GB came from SEM observation, which showed an increased stacking density of GB along the sample thickness. Experimental results indicated that the processing method with co‐extrusion/gradient distribution/2‐dimensional mixing can serve as a new way to produce a filled type of PGM and is worthy of further investigation.The prepared polyethylene/glass bead PGM; the graph illustrates the glass bead concentration gradient across the sample thickness.magnified imageThe prepared polyethylene/glass bead PGM; the graph illustrates the glass bead concentration gradient across the sample thickness.
An Analysis on Enhancement of Fatigue Durability of Polyurethane by Incorporating Organoclay Nanofillers
Authors: Jin Jie , Chen Lei , Song Mo , Yao Kejian 
Published: November 2006

AbstractSummary: One of the important applications of PUEs is as damping materials such as the spring aids used in cars, which need to have excellent cyclic fatigue durability. Our results show that the fatigue durability of PUE can be significantly improved by incorporating organoclay. The best result was obtained for 3 wt.‐% organoclay, and the fatigue durability of the PUE‐organoclay nanocomposites was increased on an average to about ten times that of pure PUE. The addition of organoclay resulted in a reduction in the size of hard‐segment domains. The organoclay nanoplatelets show reversible deformation behaviour during a fatigue test confirmed by WAXD and computer simulation. These could benefit in stopping crack propagation, releasing concentrated stress and giving rise to fatigue resistance.Schematic diagram of d‐spacing on nanoscale change during stretching.magnified imageSchematic diagram of d‐spacing on nanoscale change during stretching.
Intercalation of Diphenyl Sulfide into Nanogalleries and Preparation of Poly(p‐phenylenesulfide)‐Based Nanocomposites
Authors: Saito Tomotaka , Okamoto Masami , Hiroi Ryoichi , Yamamoto Minoru , Shiroi Takashi 
Published: November 2006

AbstractSummary: For the reference system of PPS‐based nanocomposites, we investigated the intercalation behavior of DFS molecules into nano galleries based on OMLFs consisting of different types of intercalants and nanofillers with different surface charge densities. The smaller initial interlayer opening led to the larger interlayer expansion, regardless of the miscibility between the intercalant and DFS. We examined the preparation of PPS‐based nanocomposites with and/or without shear processing at 300 °C. The finer dispersion of OMLFs in the nanocomposite was observed when using OMLF having small initial interlayer opening. The delamination of the stacked nanofillers was governed by the initial interlayer opening, whereas the uniform dispersion of the nanofillers was affected by the shear.Plot of initial interlayer opening versus Δ opening for various OMLFs intercalated with DFS.magnified imagePlot of initial interlayer opening versus Δ opening for various OMLFs intercalated with DFS.
Nanofibrous Sugar Sticks Electrospun from Glycopolymers for Protein Separation via Molecular Recognition
Authors: Yang Qian , Wu Jian , Li Jun‐Jie , Hu Meng‐Xin , Xu Zhi‐Kang 
Published: November 2006

AbstractSummary: Nanofibrous sugar sticks with linear PANCGAMA and cyclic PANCAG glucose pendants were fabricated by electrospinning from acrylonitrile‐based glycopolymers. Field emission scanning electron microscope was used to characterize the morphologies of the nanofibers. Utilizing the specific carbohydrate‐protein interaction, these two kinds of nanofiber mats were applied to separate the protein mixtures. Con A and BSA were used as model proteins. The Con A/BSA mixture solution was isolated successfully by selective adsorption of Con A to the cyclic glucose pendants on the PANCAG nanofibrous sugar sticks. However, PANCGAMA nanofibers showed almost no selectivity for these two proteins due to the poor specificity between linear glucose pendants and Con A.Typical SEM images of nanofibers fabricated from PANCAG1.magnified imageTypical SEM images of nanofibers fabricated from PANCAG1.
Synthesis and Characterization of Novel Glycerol‐Derived Polycarbonates with Pendant Hydroxyl Groups
Authors: Mei Hujie , Zhong Zhenlin , Long Feifu , Zhuo Renxi 
Published: November 2006

AbstractSummary: A novel type of glycerol‐derived, water‐soluble polycarbonate with pendant, primary hydroxyl groups was prepared from 2‐(2‐benzyloxyethoxy)trimethylene carbonate (BETC). Ring‐opening polymerization of BETC and 2,2‐dimethyltrimethylene carbonate (DTC) gave narrow distribution of homopolymers or random copolymers with high molecular weights. The protecting benzyl groups were removed by catalyzed hydrogenation at atmosphere H2 pressure to give hydroxyl polycarbonates without observable changes on the polymer backbone and molecular weight distribution. The hydrophilicity of the copolymers increases with the increase in the hydrophilic glycerol‐derived carbonate content.Synthesis of the glycerol‐derived polycarbonate.magnified imageSynthesis of the glycerol‐derived polycarbonate.
New Approach to the Synthesis of Polyacrylamide in Miniemulsified Systems
Authors: Blagodatskikh Inesa , Tikhonov Vladimir , Ivanova Elena , Landfester Katharina , Khokhlov Alexei 
Published: November 2006

AbstractSummary: A new approach to the preparation of water soluble polymer in inverse miniemulsions is proposed. A redox initiation system consisting of ceric ions and carbohydrate‐based surfactant Span 60 as a reducing agent is successfully used for the polymerization of AAm. This initiation system provides chain nucleation and growth near interfacial boundaries. As a result, stable uniform latex with particle radius of about 50–70 nm is obtained. The prepared PAAm has a rather high $\overline M _{\rm w}$ of up to about 2 × 106 Da.
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Autopsy‐proven Huntington's disease with 29 trinucleotide repeats
Authors: Kenney Christopher , Powell Suzanne , Jankovic Joseph 
Published: November 2006

AbstractHuntington's disease (HD) is a neurodegenerative disorder associated with expansion of CAG trinucleotide repeats in the huntingtin gene. A minimum of 36 CAG repeats is usually reported in patients with clinical features of HD; 30 to 35 repeats represent an intermediate range. Here we report a 65‐year‐old male with autopsy‐proven HD and 29 CAG repeats. © 2006 Movement Disorder Society
Movement Disorder Society‐sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS‐UPDRS): Process, format, and clinimetric testing plan
Authors: Goetz Christopher G. , Fahn Stanley , Martinez‐Martin Pablo , Poewe Werner , Sampaio Cristina , Stebbins Glenn T. , Stern Matthew B. , Tilley Barbara C. , Dodel Richard , Dubois Bruno , Holloway Robert , Jankovic Joseph , Kulisevsky Jaime , Lang Anthony E. , Lees Andrew , Leurgans Sue , LeWitt Peter A. , Nyenhuis David , Olanow C. Warren , Rascol Olivier , Schrag Anette , Teresi Jeanne A. , Van Hilten Jacobus J. , LaPelle Nancy 
Published: November 2006

AbstractThis article presents the revision process, major innovations, and clinimetric testing program for the Movement Disorder Society (MDS)–sponsored revision of the Unified Parkinson's Disease Rating Scale (UPDRS), known as the MDS‐UPDRS. The UPDRS is the most widely used scale for the clinical study of Parkinson's disease (PD). The MDS previously organized a critique of the UPDRS, which cited many strengths, but recommended revision of the scale to accommodate new advances and to resolve problematic areas. An MDS‐UPDRS committee prepared the revision using the recommendations of the published critique of the scale. Subcommittees developed new material that was reviewed by the entire committee. A 1‐day face‐to‐face committee meeting was organized to resolve areas of debate and to arrive at a working draft ready for clinimetric testing. The MDS‐UPDRS retains the UPDRS structure of four parts with a total summed score, but the parts have been modified to provide a section that integrates nonmotor elements of PD: I, Nonmotor Experiences of Daily Living; II, Motor Experiences of Daily Living; III, Motor Examination; and IV, Motor Complications. All items have five response options with uniform anchors of 0 = normal, 1 = slight, 2 = mild, 3 = moderate, and 4 = severe. Several questions in Part I and all of Part II are written as a patient/caregiver questionnaire, so that the total rater time should remain approximately 30 minutes. Detailed instructions for testing and data acquisition accompany the MDS‐UPDRS in order to increase uniform usage. Multiple language editions are planned. A three‐part clinimetric program will provide testing of reliability, validity, and responsiveness to interventions. Although the MDS‐UPDRS will not be published until it has successfully passed clinimetric testing, explanation of the process, key changes, and clinimetric programs allow clinicians and researchers to understand and participate in the revision process. © 2006 Movement Disorder Society
Dilation‐free graphs in the l1 metric
Authors: Cáceres J. , Grima C.I. , Márquez A. , Moreno‐González A. 
Published: November 2006

AbstractThe dilation‐free graph of a planar point set S is a graph that spans S in such a way that the distance between two points in the graph is no longer than their planar distance. Metrically speaking, those graphs are equivalent to complete graphs; however they have far fewer edges when considering the Manhattan distance (we give here an upper bound on the number of saved edges). This article provides several theoretical, algorithmic, and complexity features of dilation‐free graphs in the l1‐metric, giving several construction algorithms and proving some of their properties. Moreover, special attention is paid to the planar case due to its applications in the design of printed circuit boards. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 49(2), 168–174 2007
Comparison of linear and classical velocity update rules in particle swarm optimization: notes on scale and frame invariance
Authors: Wilke Daniel N. , Kok Schalk , Groenwold Albert A. 
Published: November 2006

AbstractIn this paper we investigate whether the particle swarm optimization (PSO) algorithm is invariant of the scale and frame (i.e. translation and rotation) in which an objective function is posed. To do so, we study the linear and classical velocity update rules. We will show that thelinearvelocity update rule is scale and frameinvariant, but that theclassicalvelocity update rule lacksrotational invariance.It is known that the linear velocity update rule lacks diversity, resulting in particle trajectories that collapse to line searches. In contrast, the classical velocity update rule maintains diverse (space filling) particle trajectories.To illustrate that diversity and invariance are not necessarily exclusive, we propose a new velocity update rule. This update rule, which is just one example of many possible formulations, is rotationally invariant and at the same time directionally diverse. This is achieved through consistent perturbation of the search directions.We quantify the (in)variance and performance of the three different implementations using a popular test set. The test problems are evaluated in both unrotated and arbitrarily rotated reference frames. Copyright © 2006 John Wiley & Sons, Ltd.
A Frobenius solution to the scaled boundary finite element equations in frequency domain for bounded media
Authors: Yang Z. J. , Deeks A. J. , Hao H. 
Published: November 2006

AbstractThe scaled boundary finite element method (FEM) is a recently developed semi‐analytical numerical approach combining advantages of the FEM and the boundary element method. Although for elastostatics, the governing homogeneous differential equations in the radial co‐ordinate can be solved analytically without much effort, an analytical solution to the non‐homogeneous differential equations in frequency domain for elastodynamics has so far only been obtained by a rather tedious series‐expansion procedure. This paper develops a much simpler procedure to obtain such an analytical solution by increasing the number of power series in the solution until the required accuracy is achieved. The procedure is applied to an extensive study of the steady‐state frequency response of a square plate subjected to harmonic excitation. Comparison of the results with those obtained using ABAQUS shows that the new method is as accurate as a detailed finite element model in calculating steady‐state responses for a wide range of frequencies using only a fraction of the degrees of freedom required in the latter. Copyright © 2006 John Wiley & Sons, Ltd.
On convergence of certain finite volume difference discretizations for 1D poroelasticity interface problems
Authors: Ewing Richard E. , Iliev Oleg P. , Lazarov Raytcho D. , Naumovich Anna 
Published: November 2006

AbstractIn the article two finite difference schemes for the 1D poroelasticity equations (Biot model) with discontinuous coefficients are derived, analyzed, and numerically tested. A recent discretization [Gaspar et al., Appl Numer Math 44 (2003), 487–506] of these equations with constant coefficients on a staggered grid is used as a basis. Special attention is given to the interfaces and as a result a scheme with harmonic averaging of the coefficients is derived. Convergence rate of O(h3/2) in a discrete H1‐norm for both the pressure and the displacement is established in the case of an arbitrary position of the interface. Further, rate of O(h2) is proven for the case when the interface coincides with a grid node. Following an approach applied to second‐order elliptic equations in [Ewing et al., SIAM J Sci Comp 23(4) (2001), 1334–1350] we derive a modified and more accurate discretization that gives second‐order convergence of the fluid velocity and the stress of the solid. Finally, numerical experiments of model problems that confirm the theoretical considerations are presented. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2007
Unified approach for open‐loop optimal control
Authors: Imura Y. , Naidu D. S. 
Published: November 2006

AbstractWe develop a unified approach for the necessary conditions for optimization ofopen‐loopcontrol systems, starting from the basic principles of calculus of variations. The unified approach results are simultaneously applicable to both shift (q)‐operator‐based, discrete‐time systems and the derivative (d/dt)‐operator‐based, continuous‐time systems. It is shown that the optimal condition results that are now obtained separately for continuous‐time and discrete‐time systems can be easily obtained from the unified approach. An illustrative example is given. Copyright © 2006 John Wiley & Sons, Ltd.
Selective binding of nanoparticles on surfaces and into polymeric matrices via directed hydrogen bonding interactions
Authors: Binder Wolfgang H. , Zirbs Ronald , Kienberger Ferry , Hinterdorfer Peter 
Published: November 2006

AbstractThe attachment of nanoparticles (NPs) onto planar surfaces and into specific phases of block copolymers is an important prerequisite for exerting their function on/in matrices for application in the field of nanotechnology. Besides non‐directional binding modes (i.e. interfacial ordering effects) most known methods rely on intermolecular ordering forces to mediate binding of NPs onto surfaces. The approach towards NP‐binding onto surfaces relies on directed, multiple hydrogen bonding systems. In this study the modular generation of surfaces and bulk‐phases with hydrogen bonding receptors and the stable binding of the NPs onto the derivatized surfaces by atomic force microscopy (AFM) are reported. To this respect surfaces presenting Hamilton‐type receptors (displaying association constants > 3 × 104 M−1) using Sharpless‐1,3‐dipolar cycloaddition reactions are prepared in high efficiency. Nanoparticle binding is studied with Au‐NPs surface modified with barbituric acid‐receptors. Binding of the particles to a surface presenting 100 mol% of receptor shows a highly dense packed layer of Au‐NPs on the surface as seen by AFM measurements. The density of the receptors is the important factor in controlling a selective binding process, achieving > 100 fold binding selectivity. The present approach opens an efficient and general mode to direct nanoparticle assembly onto nanoscaled surfaces. Copyright © 2006 John Wiley & Sons, Ltd.